14 CFR 25.1505 - Maximum operating limit speed.
2010-01-01
... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Maximum operating limit speed. 25.1505... Operating Limitations § 25.1505 Maximum operating limit speed. The maximum operating limit speed (V MO/M MO airspeed or Mach Number, whichever is critical at a particular altitude) is a speed that may not...
Evaluating the time limit at maximum aerobic speed in elite swimmers. Training implications.
Renoux, J C
2001-12-01
The aim of the present study was to make use of the concepts of maximum aerobic speed (MAS) and time limit (tlim) in order to determine the relationship between these two elements, and this in an attempt to significantly improve both speed and swimming performance during a training season. To this same end, an intermittent training model was used, which was adapted to the value obtained for the time limit at maximum aerobic speed. During a 12 week training period, the maximum aerobic speed for a group of 9 top-ranking varsity swimmers was measured on two occasions, as was the tlim. The values generated indicated that: 1) there was an inverse relationship between MAS and the time this speed could be maintained, thus confirming the studies by Billat et al. (1994b); 2) a significant increase in MAS occurred over the 12 week period, although no such evolution was seen for the tlim; 3) there was an improvement in results; 4) the time limit could be used in designing a training program based on intermittent exercises. In addition, results of the present study should allow swimming coaches to draw up individualized training programs for a given swimmer by taking into consideration maximum aerobic speed, time limit and propelling efficiency.
Liang Xu
2015-01-01
Full Text Available Aiming to reduce the number of crashes caused by speeding at night on road section with a crosswalk, a study was conducted on the maximum speed limit and safe average luminance at night. In order to investigate the potential relationship between drivers’ recognitive characteristics and driving speed under different road lighting features, data of remaining driving time (period from the time that crossing pedestrian is recognized to the time that vehicle arrives at crosswalk with an uniform speed were recorded. The results of the data analysis show that it is more difficult for divers to recognize crossing pedestrian at night when a single pedestrian is statistic and wears dark clothes. The remaining driving time decreases with the increase of driving speed and the decrease of road luminance. With the collected data, several multivariate nonlinear regression models were established to capture the relationship among the variables of remaining driving time at night, the driving speed, and the average luminance. Then the modeling results were used to develop the reasonable speed limit and safe average luminance by physical equations. The case studies are also introduced at the end of the paper.
OECD Maximum Residue Limit Calculator
With the goal of harmonizing the calculation of maximum residue limits (MRLs) across the Organisation for Economic Cooperation and Development, the OECD has developed an MRL Calculator. View the calculator.
2010-07-01
... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Speed limits. 401.28 Section 401... TRANSPORTATION SEAWAY REGULATIONS AND RULES Regulations Seaway Navigation § 401.28 Speed limits. (a) The maximum speed over the bottom for a vessel of more than 12 m in overall length shall be regulated so as not...
Guidelines for setting speed limits
Wium, DJW
1986-02-01
Full Text Available A method is described for setting the speed limit for a particular road section. Several speed limits based on different criteria are described for each of nine traffic and road factors. The most appropriate speed limit for each relevant factor...
1981-05-01
time eases the interpretation: U2 Lx -4-- where VT is the value of time (dollars (1975) per hour) V is the value of a life (dollars (1975) per L person...that for an individual, the optimal speed depends positively on his value of time and negatively on his valuation of his own life, his subjective...turn to equation (1) once again and solve for the ratio of the value of a life to the value of time , or 1 P s 2 GaS VL SP VT VT az as Rearranging
Generalized Geometric Quantum Speed Limits
Pires, Diego Paiva; Cianciaruso, Marco; Céleri, Lucas C.; Adesso, Gerardo; Soares-Pinto, Diogo O.
2016-04-01
The attempt to gain a theoretical understanding of the concept of time in quantum mechanics has triggered significant progress towards the search for faster and more efficient quantum technologies. One of such advances consists in the interpretation of the time-energy uncertainty relations as lower bounds for the minimal evolution time between two distinguishable states of a quantum system, also known as quantum speed limits. We investigate how the nonuniqueness of a bona fide measure of distinguishability defined on the quantum-state space affects the quantum speed limits and can be exploited in order to derive improved bounds. Specifically, we establish an infinite family of quantum speed limits valid for unitary and nonunitary evolutions, based on an elegant information geometric formalism. Our work unifies and generalizes existing results on quantum speed limits and provides instances of novel bounds that are tighter than any established one based on the conventional quantum Fisher information. We illustrate our findings with relevant examples, demonstrating the importance of choosing different information metrics for open system dynamics, as well as clarifying the roles of classical populations versus quantum coherences, in the determination and saturation of the speed limits. Our results can find applications in the optimization and control of quantum technologies such as quantum computation and metrology, and might provide new insights in fundamental investigations of quantum thermodynamics.
Generalized Geometric Quantum Speed Limits
Diego Paiva Pires
2016-06-01
Full Text Available The attempt to gain a theoretical understanding of the concept of time in quantum mechanics has triggered significant progress towards the search for faster and more efficient quantum technologies. One of such advances consists in the interpretation of the time-energy uncertainty relations as lower bounds for the minimal evolution time between two distinguishable states of a quantum system, also known as quantum speed limits. We investigate how the nonuniqueness of a bona fide measure of distinguishability defined on the quantum-state space affects the quantum speed limits and can be exploited in order to derive improved bounds. Specifically, we establish an infinite family of quantum speed limits valid for unitary and nonunitary evolutions, based on an elegant information geometric formalism. Our work unifies and generalizes existing results on quantum speed limits and provides instances of novel bounds that are tighter than any established one based on the conventional quantum Fisher information. We illustrate our findings with relevant examples, demonstrating the importance of choosing different information metrics for open system dynamics, as well as clarifying the roles of classical populations versus quantum coherences, in the determination and saturation of the speed limits. Our results can find applications in the optimization and control of quantum technologies such as quantum computation and metrology, and might provide new insights in fundamental investigations of quantum thermodynamics.
49 CFR 174.86 - Maximum allowable operating speed.
2010-10-01
... 49 Transportation 2 2010-10-01 2010-10-01 false Maximum allowable operating speed. 174.86 Section... operating speed. (a) For molten metals and molten glass shipped in packagings other than those prescribed in § 173.247 of this subchapter, the maximum allowable operating speed may not exceed 24 km/hour (15...
40 CFR 94.107 - Determination of maximum test speed.
2010-07-01
... specified in 40 CFR 1065.510. These data points form the lug curve. It is not necessary to generate the... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Determination of maximum test speed... Determination of maximum test speed. (a) Overview. This section specifies how to determine maximum test...
2010-07-01
... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Speed limits. 4.21 Section 4... TRAFFIC SAFETY § 4.21 Speed limits. (a) Park area speed limits are as follows: (1) 15 miles per hour... superintendent may designate a different speed limit upon any park road when a speed limit set forth in...
陈富坚; 黄世斌; 包惠明
2011-01-01
To solve the problems in the current deterministic method for determining a maximum speed limit for expressway operation against disastrous events, a reliability method was presented. The dynamic analysis was made for vehicle traveling at a horizontal curve of expressway, and respective maximum allowable speeds were deduced for vehicle in horizontal circular motion without sliding and that in emergency stopping without hitting an obstacle in the visual range. Based on Reliability engineering, the reliability of a maximum speed limit was defined. With safety of horizontal circular motion and emergency stopping as constraints, the performance function of the maximum speed limit was established and the model for calculation of its reliability and reliable indicator were deduced. For solution of the reliability model, Monte Carlo method was recommended due to multi-parameter high complexity of the non-linear performance function. With a self-developed program, a case study was conducted to illustrate the reliability analysis of the maximum speed limit for expressway safety management under a detrimental event. The reliability method for determining a maximum speed limit of expressway operation is helpful for improving traffic safety.%针对灾变事件下高速公路安全管理中采用定值型限速标准存在的问题,对基于可靠性的限速标准进行了探讨.通过对高速公路平曲线路段车辆行驶的动力学分析,推导了车辆作圆周运动而不发生横向滑移的最大允许车速,以及司机在弯道内发现障碍物而紧急安全停车的最大允许速度.以可靠性工程理论为依据,对高速公路限速标准的可靠度进行了定义,并以圆周运动安全和紧急刹车安全为约束条件建立了高速公路限速标准的功能函数,推导了相应的可靠性计算模型.针对限速标准功能函数的多参数复杂非线性特征,提出采用Monte Carlo法对限速标准可靠性计算模型进行求解.以所
2010-10-01
... 45 Public Welfare 1 2010-10-01 2010-10-01 false Speed limit. 3.26 Section 3.26 Public Welfare... INSTITUTES OF HEALTH FEDERAL ENCLAVE Traffic Regulations § 3.26 Speed limit. The speed limit is 25 miles per hour, unless otherwise posted. A driver of a vehicle may not exceed the speed limit....
Neuromuscular determinants of maximum walking speed in well-functioning older adults.
Clark, David J; Manini, Todd M; Fielding, Roger A; Patten, Carolynn
2013-03-01
Maximum walking speed may offer an advantage over usual walking speed for clinical assessment of age-related declines in mobility function that are due to neuromuscular impairment. The objective of this study was to determine the extent to which maximum walking speed is affected by neuromuscular function of the lower extremities in older adults. We recruited two groups of healthy, well functioning older adults who differed primarily on maximum walking speed. We hypothesized that individuals with slower maximum walking speed would exhibit reduced lower extremity muscle size and impaired plantarflexion force production and neuromuscular activation during a rapid contraction of the triceps surae muscle group (soleus (SO) and gastrocnemius (MG)). All participants were required to have usual 10-meter walking speed of >1.0m/s. If the difference between usual and maximum 10m walking speed was 0.6m/s, the individual was assigned to the "Faster" group (n=12). Peak rate of force development (RFD) and rate of neuromuscular activation (rate of EMG rise) of the triceps surae muscle group were assessed during a rapid plantarflexion movement. Muscle cross sectional area of the right triceps surae, quadriceps and hamstrings muscle groups was determined by magnetic resonance imaging. Across participants, the difference between usual and maximal walking speed was predominantly dictated by maximum walking speed (r=.85). We therefore report maximum walking speed (1.76 and 2.17m/s in Slower and Faster, ptriceps surae (p=.44), quadriceps (p=.76) and hamstrings (p=.98). MG rate of EMG rise was positively associated with RFD and maximum 10m walking speed, but not the usual 10m walking speed. These findings support the conclusion that maximum walking speed is limited by impaired neuromuscular force and activation of the triceps surae muscle group. Future research should further evaluate the utility of maximum walking speed for use in clinical assessment to detect and monitor age
36 CFR 1004.21 - Speed limits.
2010-07-01
... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Speed limits. 1004.21 Section... limits. (a) Speed limits in the area administered by the Presidio Trust are as follows: (1) 15 miles per... Presidio Trust roads. (b) The Board may designate a different speed limit upon any Presidio Trust road...
2010-10-01
... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Speed limits. 38.13 Section 38.13 Wildlife... NATIONAL WILDLIFE REFUGE SYSTEM MIDWAY ATOLL NATIONAL WILDLIFE REFUGE Prohibitions § 38.13 Speed limits. No person on Midway Atoll National Wildlife Refuge will exceed the speed limit for automobiles,...
32 CFR 935.132 - Speed limits.
2010-07-01
... 32 National Defense 6 2010-07-01 2010-07-01 false Speed limits. 935.132 Section 935.132 National... WAKE ISLAND CODE Motor Vehicle Code § 935.132 Speed limits. Each person operating a motor vehicle on..., or both; and (b) That does not exceed 40 miles an hour or such lesser speed limit as may be posted....
Improving homogeneity by dynamic speed limit systems.
Nes, N. van Brandenberg, S. & Twisk, D.A.M.
2010-01-01
Homogeneity of driving speeds is an important variable in determining road safety; more homogeneous driving speeds increase road safety. This study investigates the effect of introducing dynamic speed limit systems on homogeneity of driving speeds. A total of 46 subjects twice drove a route along 12
The Optimum Speed Limit. Revised.
1983-07-01
Relating U, and U to the values of life and time eases the interpretation: (2) U, -vX; (2a) U, -V. XI where: V, is the dollar value of time (more precisely...by (3) I V [ as ;as Equation (3) shows that for an individual, the optimal speed depends positively on his value of time and negatively on his...fatality rates to driving speed and gas mileage to speed. The value of time and the value of a life are harder to determine because they cannot be
Kinematic analysis of sprinting pickup acceleration versus maximum sprinting speed
S. MANZER
2016-10-01
Full Text Available Pickup acceleration and maximum sprinting speed are two essential phases of the 100-m sprint with variant sprinting speed, step length, frequency and technique. The aim of the study was to describe and compare the kinematic parameters of both sprint variants. Hypothetically it was assumed to find differences in sprinting speed, step length, flight and contact times as well as between the body angles of different key positions. From 8 female and 8 male (N=16 track and field junior athletes a double stride of both sprint variants was filmed (200 Hz from a sagittal position and the 10-m-sprint time was measured using triple light barriers. Kinematic data for sprinting speed and angles of knee, hip and ankle were compared with an analysis of variance with repeated measures. The sprinting speed was 7.7 m/s and 8.0 m/s (female and 8.4 m/s and 9.2 m/s (male with significantly higher values of step length, flight time and shorter ground contact time during maximum sprinting speed. Because of the longer flight time, it is possible to place the foot closer to the body but with a more extended knee on the ground. These characteristics can be used as orientation for technique training.
The maximum force in a column under constant speed compression
Kuzkin, Vitaly A
2015-01-01
Dynamic buckling of an elastic column under compression at constant speed is investigated assuming the first-mode buckling. Two cases are considered: (i) an imperfect column (Hoff's statement), and (ii) a perfect column having an initial lateral deflection. The range of parameters, where the maximum load supported by a column exceeds Euler static force is determined. In this range, the maximum load is represented as a function of the compression rate, slenderness ratio, and imperfection/initial deflection. Considering the results we answer the following question: "How slowly the column should be compressed in order to measure static load-bearing capacity?" This question is important for the proper setup of laboratory experiments and computer simulations of buckling. Additionally, it is shown that the behavior of a perfect column having an initial deflection differ significantlys form the behavior of an imperfect column. In particular, the dependence of the maximum force on the compression rate is non-monotoni...
Maximum speeds and alpha angles of flowing avalanches
McClung, David; Gauer, Peter
2016-04-01
A flowing avalanche is one which initiates as a slab and, if consisting of dry snow, will be enveloped in a turbulent snow dust cloud once the speed reaches about 10 m/s. A flowing avalanche has a dense core of flowing material which dominates the dynamics by serving as the driving force for downslope motion. The flow thickness typically on the order of 1 -10 m which is on the order of about 1% of the length of the flowing mass. We have collected estimates of maximum frontal speed um (m/s) from 118 avalanche events. The analysis is given here with the aim of using the maximum speed scaled with some measure of the terrain scale over which the avalanches ran. We have chosen two measures for scaling, from McClung (1990), McClung and Schaerer (2006) and Gauer (2012). The two measures are the √H0-;√S0-- (total vertical drop; total path length traversed). Our data consist of 118 avalanches with H0 (m)estimated and 106 with S0 (m)estimated. Of these, we have 29 values with H0 (m),S0 (m)and um (m/s)estimated accurately with the avalanche speeds measured all or nearly all along the path. The remainder of the data set includes approximate estimates of um (m/s)from timing the avalanche motion over a known section of the path where approximate maximum speed is expected and with either H0or S0or both estimated. Our analysis consists of fitting the values of um/√H0--; um/√S0- to probability density functions (pdf) to estimate the exceedance probability for the scaled ratios. In general, we found the best fits for the larger data sets to fit a beta pdf and for the subset of 29, we found a shifted log-logistic (s l-l) pdf was best. Our determinations were as a result of fitting the values to 60 different pdfs considering five goodness-of-fit criteria: three goodness-of-fit statistics :K-S (Kolmogorov-Smirnov); A-D (Anderson-Darling) and C-S (Chi-squared) plus probability plots (P-P) and quantile plots (Q-Q). For less than 10% probability of exceedance the results show that
Radiation Pressure Acceleration: the factors limiting maximum attainable ion energy
Bulanov, S S; Schroeder, C B; Bulanov, S V; Esirkepov, T Zh; Kando, M; Pegoraro, F; Leemans, W P
2016-01-01
Radiation pressure acceleration (RPA) is a highly efficient mechanism of laser-driven ion acceleration, with with near complete transfer of the laser energy to the ions in the relativistic regime. However, there is a fundamental limit on the maximum attainable ion energy, which is determined by the group velocity of the laser. The tightly focused laser pulses have group velocities smaller than the vacuum light speed, and, since they offer the high intensity needed for the RPA regime, it is plausible that group velocity effects would manifest themselves in the experiments involving tightly focused pulses and thin foils. However, in this case, finite spot size effects are important, and another limiting factor, the transverse expansion of the target, may dominate over the group velocity effect. As the laser pulse diffracts after passing the focus, the target expands accordingly due to the transverse intensity profile of the laser. Due to this expansion, the areal density of the target decreases, making it trans...
Improving speed behaviour : the potential of in-car speed assistance and speed limit credibility.
Nes, C.N. van Houtenbos, M. & Schagen, I.N.L.G. van
2009-01-01
Speeding is still a common practice on many roads and it contributes to a significant number of crashes. Two new approaches to solve speeding issues are focused on: intelligent speed assistance systems (ISA) and speed limit credibility. Research has indicated that ISA is promising with respect to im
Is there a speed limit for trapped ion quantum computers?
Lau, Hoi-Kwan
2011-01-01
We investigate a speed limit for quantum processing for trapped ion quantum computers using the Kielpinski-Monroe-Wineland (KMW) architecture. The limiting speed for single-ion shuttling between a storage trap and a logic trap is constrained by the need to avoid excessive ion heating, excessive dephasing and decoherence due to the D.C. Stark effect. We estimate the relative significance of these errors and find that dephasing is dominant. We find that the minimum magnitude of dephasing is quadratic in the time of flight, and an inverse cubic in the operational time scale; from these relations, a limit on the operational speed of ion-trap quantum computers is deduced. Without subsequent phase correction, the maximum speed a qubit can be transferred across a 100 micron-long trap, without excessive error, in about 10 ns for calcium ion and 50 ps for beryllium ion.
Time-limited optimal dynamics beyond the Quantum Speed Limit
Gajdacz, Miroslav; Das, Kunal K.; Arlt, Jan
2015-01-01
-off expressed in terms of the direct Hilbert velocity provides a robust prediction of the quantum speed limit and allows to adapt the control optimization such that it yields a predefined fidelity. The results are verified numerically in a multilevel system with a constrained Hamiltonian, and a classification......The quantum speed limit sets the minimum time required to transfer a quantum system completely into a given target state. At shorter times the higher operation speed has to be paid with a loss of fidelity. Here we quantify the trade-off between the fidelity and the duration in a system driven...
2010-07-01
... as specified in 40 CFR 1065.610. This is the maximum in-use engine speed used for calculating the NOX... procedures of 40 CFR part 1065, based on the manufacturer's design and production specifications for the..., power density, and maximum in-use engine speed. 1042.140 Section 1042.140 Protection of...
A Note on k-Limited Maximum Base
Yang Ruishun; Yang Xiaowei
2006-01-01
The problem of k-limited maximum base was specified into two special problems of k-limited maximum base; that is, let subset D of the problem of k-limited maximum base be an independent set and a circuit of the matroid, respectively. It was proved that under this circumstance the collections of k-limited base satisfy base axioms. Then a new matroid was determined, and the problem of k-limited maximum base was transformed to the problem of maximum base of this new matroid. Aiming at the problem, two algorithms, which in essence are greedy algorithms based on former matroid, were presented for the two special problems of k-limited maximum base. They were proved to be reasonable and more efficient than the algorithm presented by Ma Zhongfan in view of the complexity of algorithm.
Theme II. Speed limits and the driver. Advisory speed limits: Should they be expanded or not?
Wegman, F.C.M.
1985-01-01
According to Dutch legislation, advisory speed limits should only be used on curves with a small radius, although there has been an increasing demand in recent years for w wider application of advisory speed limits. The behaviour of drivers on curves and the forces working on the vehicle and its occ
49 CFR 213.57 - Curves; elevation and speed limitations.
2010-10-01
... the following formula— ER22JN98.001 Where— Vmax = Maximum allowable operating speed (miles per hour... appendix A is a table of maximum allowable operating speed computed in accordance with this formula for... following formula— ER22JN98.002 Where— Vmax = Maximum allowable operating speed (miles per hour)....
5 CFR 550.105 - Biweekly maximum earnings limitation.
2010-01-01
... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Biweekly maximum earnings limitation. 550.105 Section 550.105 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PAY ADMINISTRATION (GENERAL) Premium Pay Maximum Earnings Limitations § 550.105 Biweekly...
5 CFR 550.106 - Annual maximum earnings limitation.
2010-01-01
... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Annual maximum earnings limitation. 550.106 Section 550.106 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PAY ADMINISTRATION (GENERAL) Premium Pay Maximum Earnings Limitations § 550.106 Annual...
Time-limited optimal dynamics beyond the Quantum Speed Limit
Gajdacz, Miroslav; Das, Kunal K.; Arlt, Jan
2015-01-01
The quantum speed limit sets the minimum time required to transfer a quantum system completely into a given target state. At shorter times the higher operation speed has to be paid with a loss of fidelity. Here we quantify the trade-off between the fidelity and the duration in a system driven...... by a time-varying control. The problem is addressed in the framework of Hilbert space geometry offering an intuitive interpretation of optimal control algorithms. This approach leads to a necessary criterion for control optimality applicable as a measure of algorithm convergence. The time fidelity trade......-off expressed in terms of the direct Hilbert velocity provides a robust prediction of the quantum speed limit and allows to adapt the control optimization such that it yields a predefined fidelity. The results are verified numerically in a multilevel system with a constrained Hamiltonian, and a classification...
49 CFR 213.9 - Classes of track: operating speed limits.
2010-10-01
... 49 Transportation 4 2010-10-01 2010-10-01 false Classes of track: operating speed limits. 213.9... speed limits. (a) Except as provided in paragraph (b) of this section and §§ 213.57(b), 213.59(a), 213.113(a), and 213.137(b) and (c), the following maximum allowable operating speeds apply— Over...
Maximum-speed curve-running biomechanics of sprinters with and without unilateral leg amputations.
Taboga, Paolo; Kram, Rodger; Grabowski, Alena M
2016-03-01
On curves, non-amputees' maximum running speed is slower on smaller radii and thought to be limited by the inside leg's mechanics. Similar speed decreases would be expected for non-amputees in both counterclockwise and clockwise directions because they have symmetric legs. However, sprinters with unilateral leg amputation have asymmetric legs, which may differentially affect curve-running performance and Paralympic competitions. To investigate this and understand the biomechanical basis of curve running, we compared maximum curve-running (radius 17.2 m) performance and stride kinematics of six non-amputee sprinters and 11 sprinters with a transtibial amputation. Subjects performed randomized, counterbalanced trials: two straight, two counterclockwise curves and two clockwise curves. Non-amputees and sprinters with an amputation all ran slower on curves compared with straight running, but with different kinematics. Non-amputees ran 1.9% slower clockwise compared with counterclockwise (Prunning. Sprinters with an amputation also reduced stride length in both curve-running directions, but reduced stride frequency only on curves with the affected leg on the inside. During curve running, non-amputees and athletes with an amputation had longer contact times with their inside compared with their outside leg, suggesting that the inside leg limits performance. For sprinters with an amputation, the prolonged contact times of the affected versus unaffected leg seem to limit maximum running speed during both straight running and running on curves with the affected leg on the inside.
Quantum speed limits in open system dynamics.
del Campo, A; Egusquiza, I L; Plenio, M B; Huelga, S F
2013-02-01
Bounds to the speed of evolution of a quantum system are of fundamental interest in quantum metrology, quantum chemical dynamics, and quantum computation. We derive a time-energy uncertainty relation for open quantum systems undergoing a general, completely positive, and trace preserving evolution which provides a bound to the quantum speed limit. When the evolution is of the Lindblad form, the bound is analogous to the Mandelstam-Tamm relation which applies in the unitary case, with the role of the Hamiltonian being played by the adjoint of the generator of the dynamical semigroup. The utility of the new bound is exemplified in different scenarios, ranging from the estimation of the passage time to the determination of precision limits for quantum metrology in the presence of dephasing noise.
Pranoto Hadi
2016-01-01
Full Text Available Driving is one of the conditions when the driver should be given special attention to make the motor vehicle in driving way and the driver should be in a good condition. However, the problem is in a certain condition the driver lost their control speed due to their target and minimize the driving time and it led the high potential to accident. Therefore, speed limiter which applied in the bus is urgently needed to reduce the accident and improve their awareness of road safety. Developed speed limiter is completed by fuel cut-off system to prevent the engine and maintain the speed. Limitation of speed be adapted by government regulation. From the results show that the highest and average speed of 136 km/h and 123.5 km/h is observed by bus speed prior to use speed limiter. After speed limiter applied in the bus, the approved maximum speed is 90 km/h. Those data approve that the speed limiter can reduce 83% from the top speed before speed limiter applied.
49 CFR 213.329 - Curves, elevation and speed limitations.
2010-10-01
... by the following formula: ER22JN98.009 Where— Vmax = Maximum allowable operating speed (miles per... with this formula for various elevations and degrees of curvature for track speeds greater than 90 m.p... maximum operating speed for each curve may be determined by the following formula: ER22JN98.008...
Capó-Lugo, Carmen E; Mullens, Christopher H; Brown, David A
2012-10-11
Previous studies demonstrated that stroke survivors have a limited capacity to increase their walking speeds beyond their self-selected maximum walking speed (SMWS). The purpose of this study was to determine the capacity of stroke survivors to reach faster speeds than their SMWS while walking on a treadmill belt or while being pushed by a robotic system (i.e. "push mode"). Eighteen chronic stroke survivors with hemiplegia were involved in the study. We calculated their self-selected comfortable walking speed (SCWS) and SMWS overground using a 5-meter walk test (5-MWT). Then, they were exposed to walking at increased speeds, on a treadmill and while in "push mode" in an overground robotic device, the KineAssist, until they were tested at a speed that they could not sustain without losing balance. We recorded the time and number of steps during each trial and calculated gait speed, average cadence and average step length. Maximum walking speed in the "push mode" was 13% higher than the maximum walking speed on the treadmill and both were higher ("push mode": 61%; treadmill: 40%) than the maximum walking speed overground. Subjects achieved these faster speeds by initially increasing both step length and cadence and, once individuals stopped increasing their step length, by only increasing cadence. With post-stroke hemiplegia, individuals are able to walk at faster speeds than their SMWS overground, when provided with a safe environment that provides external forces that requires them to attempt dynamic stability maintenance at higher gait speeds. Therefore, this study suggests the possibility that, given the appropriate conditions, people post-stroke can be trained at higher speeds than previously attempted.
Capó-Lugo Carmen E
2012-10-01
Full Text Available Abstract Background Previous studies demonstrated that stroke survivors have a limited capacity to increase their walking speeds beyond their self-selected maximum walking speed (SMWS. The purpose of this study was to determine the capacity of stroke survivors to reach faster speeds than their SMWS while walking on a treadmill belt or while being pushed by a robotic system (i.e. “push mode”. Methods Eighteen chronic stroke survivors with hemiplegia were involved in the study. We calculated their self-selected comfortable walking speed (SCWS and SMWS overground using a 5-meter walk test (5-MWT. Then, they were exposed to walking at increased speeds, on a treadmill and while in “push mode” in an overground robotic device, the KineAssist, until they were tested at a speed that they could not sustain without losing balance. We recorded the time and number of steps during each trial and calculated gait speed, average cadence and average step length. Results Maximum walking speed in the “push mode” was 13% higher than the maximum walking speed on the treadmill and both were higher (“push mode”: 61%; treadmill: 40% than the maximum walking speed overground. Subjects achieved these faster speeds by initially increasing both step length and cadence and, once individuals stopped increasing their step length, by only increasing cadence. Conclusions With post-stroke hemiplegia, individuals are able to walk at faster speeds than their SMWS overground, when provided with a safe environment that provides external forces that requires them to attempt dynamic stability maintenance at higher gait speeds. Therefore, this study suggests the possibility that, given the appropriate conditions, people post-stroke can be trained at higher speeds than previously attempted.
Relationship between speed and traffic accident and speed limit on freeway
CHENG Guo-zhu; PEI Yu-long
2008-01-01
To develop an equation between discrete degree of speed and traffic accident on freeway in China and give reasonable suggestions of speed management, the relation model was established between speed standard deviation and accident rate per 100,000,000 vehicle kilometers by regression analysis. The model shows that the more discrete is the speed distribution, the higher is the accident rate, which provides theoretical gist for speed limit on freeway. It is suggested that speed limit should be set according to 85th percentile speed obtained by the relationship between 85th percentile speed and Rcc, (curvature change rate of single circular curve), anddifferent speed limits should be set for cars and trucks. Through analyzing spot speed data of eight freeways in China, regression models were established between 85th percentile speed and RCCs and 15th percentile speed and RCCs. Reasonable speed limit suggestion values are put forward through these models.
Terror birds on the run: a mechanical model to estimate its maximum running speed
Blanco, R. Ernesto; Jones, Washington W
2005-01-01
‘Terror bird’ is a common name for the family Phorusrhacidae. These large terrestrial birds were probably the dominant carnivores on the South American continent from the Middle Palaeocene to the Pliocene–Pleistocene limit. Here we use a mechanical model based on tibiotarsal strength to estimate maximum running speeds of three species of terror birds: Mesembriornis milneedwardsi, Patagornis marshi and a specimen of Phorusrhacinae gen. The model is proved on three living large terrestrial bird species. On the basis of the tibiotarsal strength we propose that Mesembriornis could have used its legs to break long bones and access their marrow. PMID:16096087
The Limiting Speed of the Bacterial Flagellar Motor
Nirody, Jasmine A; Oster, George
2015-01-01
Recent experiments on the bacterial flagellar motor have shown that the structure of this nanomachine, which drives locomotion in a wide range of bacterial species, is more dynamic than previously believed. Specifically, the number of active torque-generating units (stators) was shown to vary across applied loads. This finding invalidates the experimental evidence reporting that limiting (zero-torque) speed is independent of the number of active stators. Here, we propose that, contrary to previous assumptions, the maximum speed of the motor is not universal, but rather increases as additional torque-generators are recruited. This result arises from our assumption that stators disengage from the motor for a significant portion of their mechanochemical cycles at low loads. We show that this assumption is consistent with current experimental evidence and consolidate our predictions with arguments that a processive motor must have a high duty ratio at high loads.
Comparison of two field tests to estimate maximum aerobic speed.
Berthoin, S; Gerbeaux, M; Turpin, E; Guerrin, F; Lensel-Corbeil, G; Vandendorpe, F
1994-08-01
The measurement of maximal aerobic speed (MAS) and the prediction of maximal oxygen uptake (VO2 max) by means of field tests were carried out on 17 students studying physical education. The subjects underwent a continuous multi-stage track test (Léger and Boucher, 1980), shuttle test (Léger et al., 1984) and VO2 max measurement on a treadmill. The VO2 max values estimated using the track test (56.8 +/- 5.8 ml kg-1 min-1) were not significantly different from the values measured in the treadmill test (56.8 +/- 7.1 ml kg-1 min-1), but were higher than those estimated using the shuttle test (51.1 +/- 5.9 ml kg-1 min-1). The maximal nature of the tests was checked by measurement of heart rate and lactate concentration, taken within 2 min post-test. The means of the MAS observed in the track test (15.8 +/- 1.9 km h-1) and in the treadmill test (15.9 +/- 2.6 km h-1) were not significantly different (P > 0.10). The mean of the shuttle test MAS (13.1 +/- 1 km h-1) was significantly lower (P < 0.01) than those of the other tests. However, the MAS of the shuttle test and track test are linked. The equation for linear regression between MAS values in these two tests is MAStrack = 1.81 x MASshuttle -7.86 (r = 0.91), allowing estimation of one of these MAS values when the other is known. Thus these values may be used within diversified training.
Farrell, A P; Steffensen, J F
1987-01-01
The maximum aerobic swimming speed of Chinook salmon (Oncorhynchus tshawytscha) was measured before and after ligation of the coronary artery. Coronary artery ligation prevented blood flow to the compact layer of the ventricular myocardium, which represents 30% of the ventricular mass, and produced...... a statistically significant 35.5% reduction in maximum swimming speed. We conclude that the coronary circulation is important for maximum aerobic swimming and implicit in this conclusion is that maximum cardiac performance is probably necessary for maximum aerobic swimming performance....
Perils of using speed zone data to assess real-world compliance to speed limits.
Chevalier, Anna; Clarke, Elizabeth; Chevalier, Aran John; Brown, Julie; Coxon, Kristy; Ivers, Rebecca; Keay, Lisa
2017-04-05
Real-world driving studies, including those involving speeding alert devices and autonomous vehicles, can gauge an individual vehicle's speeding behavior by comparing measured speed with mapped speed zone data. However, there are complexities with developing and maintaining a database of mapped speed zones over a large geographic area that may lead to inaccuracies within the data set. When this approach is applied to large-scale real-world driving data or speeding alert device data to determine speeding behavior, these inaccuracies may result in invalid identification of speeding. We investigated speeding events based on service provider speed zone data. We compared service provider speed zone data (Speed Alert by Smart Car Technologies Pty Ltd., Ultimo, NSW, Australia) against a second set of speed zone data (Google Maps Application Programming Interface [API] mapped speed zones). We found a systematic error in the zones where speed limits of 50-60 km/h, typical of local roads, were allocated to high-speed motorways, which produced false speed limits in the speed zone database. The result was detection of false-positive high-range speeding. Through comparison of the service provider speed zone data against a second set of speed zone data, we were able to identify and eliminate data most affected by this systematic error, thereby establishing a data set of speeding events with a high level of sensitivity (a true positive rate of 92% or 6,412/6,960). Mapped speed zones can be a source of error in real-world driving when examining vehicle speed. We explored the types of inaccuracies found within speed zone data and recommend that a second set of speed zone data be utilized when investigating speeding behavior or developing mapped speed zone data to minimize inaccuracy in estimates of speeding.
The Change in the Maximum Wind Speed and the Impact of it on Agricultural Production
WU Jian-mei; SUN Jin-sen; SUI Gui-ling; XIE Su-he; WANG Meng
2012-01-01
Using the data on the maximum wind speed within ten minutes every month in the period 1971-2009 in Zhucheng City of Shandong Province, we conduct statistical analysis of the maximum wind speed in Zhucheng City. The results show that over thirty-nine years, the annual maximum wind speed in four seasons in Zhucheng City tends to decline. The annual maximum wind speed declines at the rate of 1.45 m/s every 10 years. It falls fastest in winter, with decline rate of 1.73 m/s every 10 years; it is close to the average annual maximum wind speed in spring and autumn, with decline rate of 1.44 m/s and 14.8 m/s every 10 years, respectively; it falls slowest in summer, and the extreme value of the maximum wind speed occurs mainly in spring. The curve of changes in the monthly maximum wind speed in Zhucheng City assumes diminishing shape of "two peaks and one trough". We conduct preliminary analysis of the windy weather situation, and put forth specific defensive measures against the hazards of strong winds in the different periods.
A study of speed limits and speed control measures for the urban arterial road
Wichuda Satiennam
2015-06-01
Full Text Available Speed limits in accordance with environment and road functions have been used as a fundamental tool for speed management and road safety. This paper presents literatures review of speed limits measure and results from the study on speed limits problem and driver attitude toward the speed limit and speed control measure. Area of study is on the arterial road where the Mittaprab Highway passed through Khon Kaen City. The study found that improper designation of road functions is the main cause of complexity and difficulty on safety management. It suggests more researches on speed limit setting methods to accommodate the road conditions of the country. In order to increase effectiveness of speed limits measure, this paper suggests transportation-related authorities to classify this area to be the urban arterial road, to set proper speed limits, and to modify the road environment in accordance with its function. More measures to enhance speed limit effectiveness and to reduce accident are included automatic speed control devices, speed limits warning signs, and advertisement signs to use the bypass route. These could enhance the effective speed management program.
Vescovi, Jason D
2014-07-01
The aim of this study was to examine the impact of maximum sprint speed on peak and mean sprint speed during youth female field hockey matches. Two high-level female field hockey teams (U-17, n = 24, and U-21, n = 20) were monitored during a 4-game international test series using global position system technology and tested for maximum sprint speed. Dependent variables were compared using a 3-factor ANOVA (age group, position, and speed classification); effect sizes (Cohen d) and confidence limits were also calculated. Maximum sprint speed was similar between age groups and positions, with faster players having greater speed than slower players (29.3 ± 0.4 vs 27.2 ± 1.1 km/h). Overall, peak match speed in youth female field hockey players reaches approximately 90% of maximum sprint speed. Absolute peak match speed and mean sprint speed during matches were similar among the age groups (except match 1) and positions (except match 2); however, peak match speed was greater for faster players in matches 3 and 4. No differences were observed in the relative proportion for mean sprint speeds for age groups or positions, but slower players consistently displayed similar relative mean sprint speeds by using a greater proportion of their maximum sprint speed.
Testing the Speed Limit for Europe
Gros, Daniel; Jimeno, Juan; Monticelli, Carlo;
While America has pushed the pedal to the metal and with alarming speed has accelerated its productivity growth, it would seem that Europe on the other hand is experiencing a lack of progress in its labour markets and a deceleration in labour productivity. In this third annual report by the CEPS...
75 FR 49815 - Maneuvering Speed Limitation Statement
2010-08-16
... time, may result in structural failure at any speed. The FAA believes the standard dictionary... regulations must undergo several economic analyses. First, Executive Order 12866 directs that each Federal...) requires agencies to analyze the economic impact of regulatory changes on small entities. Third, the Trade...
Noise and physical limits to maximum resolution of PET images
Herraiz, J.L.; Espana, S. [Dpto. Fisica Atomica, Molecular y Nuclear, Facultad de Ciencias Fisicas, Universidad Complutense de Madrid, Avda. Complutense s/n, E-28040 Madrid (Spain); Vicente, E.; Vaquero, J.J.; Desco, M. [Unidad de Medicina y Cirugia Experimental, Hospital GU ' Gregorio Maranon' , E-28007 Madrid (Spain); Udias, J.M. [Dpto. Fisica Atomica, Molecular y Nuclear, Facultad de Ciencias Fisicas, Universidad Complutense de Madrid, Avda. Complutense s/n, E-28040 Madrid (Spain)], E-mail: jose@nuc2.fis.ucm.es
2007-10-01
In this work we show that there is a limit for the maximum resolution achievable with a high resolution PET scanner, as well as for the best signal-to-noise ratio, which are ultimately related to the physical effects involved in the emission and detection of the radiation and thus they cannot be overcome with any particular reconstruction method. These effects prevent the spatial high frequency components of the imaged structures to be recorded by the scanner. Therefore, the information encoded in these high frequencies cannot be recovered by any reconstruction technique. Within this framework, we have determined the maximum resolution achievable for a given acquisition as a function of data statistics and scanner parameters, like the size of the crystals or the inter-crystal scatter. In particular, the noise level in the data as a limitation factor to yield high-resolution images in tomographs with small crystal sizes is outlined. These results have implications regarding how to decide the optimal number of voxels of the reconstructed image or how to design better PET scanners.
Using Appropriate Speed Tables Regarding to the Speed Limit of Streets
Amir Falamarzi
2014-04-01
Full Text Available In the present decade along the increasing trend of using private vehicles, calming the local streets and residential areas has been important for local authorities. There are many unsuccessful experiences of traffic calming implementations because of lacking knowledge and engineered assessment before implementing them. Considering the design speed of traffic, calming measure is an essential factor to employ these measures. Design speed of different size of speed humps is investigated in previous studies because of its circular shape but for speed tables it is unknown. In this research the design speeds of two common speed tables in the city of Tehran have been examined, 6.5 and 8.5 m speed table. For calculating the design speed of the speed tables, we asked 220 drivers to participate in our experiment by installing a GPS tracker in their vehicles and encouraging them to drive normally. Crossing speeds over 6.5 and 8.5 m speed tables have been analyzed by collecting totally 220 samples. We pick out 100 correct samples for each speed table and the 85th percentile speed has been calculated for them, consequently the results of 85th percentile calculation of the crossing speeds have been proposed as the design speeds. For 6.5 m speed table, design speed is calculated 41.5 km/h and for 8.5 m speed table, design speed is calculated 47.5 km/h. the comparison of recent findings and past finding of 9.5 m speed table which is used in Denmark with a design speed of 80 km/h reveals that 1 m increasing with the length of a 6.5 speed table plateau will result 3 km/h increase in its design speed. The findings of this research can help traffic calming experts to take in consideration of the relation between speed table physical characteristics and its design speed. Furthermore by finding the design speed of speed tables, we can choose suitable speed tables for streets with different speed limits according to the design speed of speed tables.
Maximum Likelihood Position Location with a Limited Number of References
D. Munoz-Rodriguez
2011-04-01
Full Text Available A Position Location (PL scheme for mobile users on the outskirts of coverage areas is presented. The proposedmethodology makes it possible to obtain location information with only two land-fixed references. We introduce ageneral formulation and show that maximum-likelihood estimation can provide adequate PL information in thisscenario. The Root Mean Square (RMS error and error-distribution characterization are obtained for differentpropagation scenarios. In addition, simulation results and comparisons to another method are provided showing theaccuracy and the robustness of the method proposed. We study accuracy limits of the proposed methodology fordifferent propagation environments and show that even in the case of mismatch in the error variances, good PLestimation is feasible.
INFLUENCE OF OPERABILITY CRITERIA LIMITING VALUES ON SHIP SPEED
Jasna Prpić-Oršić
2016-09-01
Full Text Available When the ship is caught in heavy seas, there are two manoeuvres that the shipmaster can undertake to avoid excessive ship motion and hull damage: changing course or voluntary speed reduction. This paper presents a study of the effect of the various voluntary speed reduction criteria to attainable speed of ship on seaway. The speed loss is calculated by taking into account wind and wave effect on ship speed, the engine and propeller performance in actual seas as well as the mass inertia of the ship. The attainable ship speed for ship in head, following and beam waves by accounting for voluntary speed reduction is estimated for various significant wave height. The criteria of slamming, deck wetness, propeller emergence, excessive accelerations and roll are taken into account. The impact of variations of the limiting values of certain criteria due to which the captain intentionally reduces the ship speed is analysed and discussed.
Luchko, Yuri; Povstenko, Yuriy
2012-01-01
In this paper, the one-dimensional time-fractional diffusion-wave equation with the fractional derivative of order $1 \\le \\alpha \\le 2$ is revisited. This equation interpolates between the diffusion and the wave equations that behave quite differently regarding their response to a localized disturbance: whereas the diffusion equation describes a process, where a disturbance spreads infinitely fast, the propagation speed of the disturbance is a constant for the wave equation. For the time fractional diffusion-wave equation, the propagation speed of a disturbance is infinite, but its fundamental solution possesses a maximum that disperses with a finite speed. In this paper, the fundamental solution of the Cauchy problem for the time-fractional diffusion-wave equation, its maximum location, maximum value, and other important characteristics are investigated in detail. To illustrate analytical formulas, results of numerical calculations and plots are presented. Numerical algorithms and programs used to produce pl...
Feedback Limits to Maximum Seed Masses of Black Holes
Pacucci, Fabio; Natarajan, Priyamvada; Ferrara, Andrea
2017-02-01
The most massive black holes observed in the universe weigh up to ∼1010 M ⊙, nearly independent of redshift. Reaching these final masses likely required copious accretion and several major mergers. Employing a dynamical approach that rests on the role played by a new, relevant physical scale—the transition radius—we provide a theoretical calculation of the maximum mass achievable by a black hole seed that forms in an isolated halo, one that scarcely merged. Incorporating effects at the transition radius and their impact on the evolution of accretion in isolated halos, we are able to obtain new limits for permitted growth. We find that large black hole seeds (M • ≳ 104 M ⊙) hosted in small isolated halos (M h ≲ 109 M ⊙) accreting with relatively small radiative efficiencies (ɛ ≲ 0.1) grow optimally in these circumstances. Moreover, we show that the standard M •–σ relation observed at z ∼ 0 cannot be established in isolated halos at high-z, but requires the occurrence of mergers. Since the average limiting mass of black holes formed at z ≳ 10 is in the range 104–6 M ⊙, we expect to observe them in local galaxies as intermediate-mass black holes, when hosted in the rare halos that experienced only minor or no merging events. Such ancient black holes, formed in isolation with subsequent scant growth, could survive, almost unchanged, until present.
Determination of Maximum Follow-up Speed of Electrode System of Resistance Projection Welders
Wu, Pei; Zhang, Wenqi; Bay, Niels
2004-01-01
the weld process settings for the stable production and high quality of products. In this paper, the maximum follow-up speed of electrode system was tested by using a special designed device which can be mounted to all types of machine and easily to be applied in industry, the corresponding mathematical......The maximum follow-up speed of electrode system represents the dynamic mechanical response capacity of resistance projection welding machines, which is important to make the diffrernce from one machine to the other and to consider the individual behavior of machines in designing or optimizing...
Second-generation speed limit map updating applications
Tradisauskas, Nerius; Agerholm, Niels; Juhl, Jens
2011-01-01
Intelligent Speed Adaptation is an Intelligent Transport System developed to significantly improve road safety in helping car drivers maintain appropriate driving behaviour. The system works in connection with the speed limits on the road network. It is thus essential to keep the speed limit map...... developed to give road authorities the opportunity to keep the speed limit map updated. However, the feedback from road authorities was insufficient. Hence a new web application based on Google Maps was made to provide easier speed limit updates for road authorities. The lessons learnt were that tools...... for map updating should preferably be made on the basis of a commercial map provider, 2 such as Google Maps and that the real challenge is to oblige road authorities to carry out updates....
Maximum Range of a Projectile Thrown from Constant-Speed Circular Motion
Poljak, Nikola
2016-11-01
The problem of determining the angle θ at which a point mass launched from ground level with a given speed v0 will reach a maximum distance is a standard exercise in mechanics. There are many possible ways of solving this problem, leading to the well-known answer of θ = π/4, producing a maximum range of D max = v0 2 / g , with g being the free-fall acceleration. Conceptually and calculationally more difficult problems have been suggested to improve student proficiency in projectile motion, with the most famous example being the Tarzan swing problem. The problem of determining the maximum distance of a point mass thrown from constant-speed circular motion is presented and analyzed in detail in this text. The calculational results confirm several conceptually derived conclusions regarding the initial throw position and provide some details on the angles and the way of throwing (underhand or overhand) that produce the maximum throw distance.
Dependency of U.S. Hurricane Economic Loss on Maximum Wind Speed and Storm Size
Zhai, Alice R
2014-01-01
Many empirical hurricane economic loss models consider only wind speed and neglect storm size. These models may be inadequate in accurately predicting the losses of super-sized storms, such as Hurricane Sandy in 2012. In this study, we examined the dependencies of normalized U.S. hurricane loss on both wind speed and storm size for 73 tropical cyclones that made landfall in the U.S. from 1988 to 2012. A multi-variate least squares regression is used to construct a hurricane loss model using both wind speed and size as predictors. Using maximum wind speed and size together captures more variance of losses than using wind speed or size alone. It is found that normalized hurricane loss (L) approximately follows a power law relation with maximum wind speed (Vmax) and size (R). Assuming L=10^c Vmax^a R^b, c being a scaling factor, the coefficients, a and b, generally range between 4-12 and 2-4, respectively. Both a and b tend to increase with stronger wind speed. For large losses, a weighted regression model, with...
Maximum Output Power Control System of Variable-Speed Small Wind Generators
Amano, Yoko; Kajiwara, Hiroyuki
This paper proposes a maximum output power control system of variable-speed small wind generators. Paying attention to an optimum rotational speed of a single phase AC wind generator which can obtain maximum output power according to natural wind speed, the proposed method adjusts the rotational speed of the single phase AC generator to the optimum rotational speed. Since this adjustment is realized on line so that it can be adapted for variable-speed wind, a generated power brake links directly with the single phase AC generator, and the rotational speed of the single phase AC generator is adjusted by controlling the current that flows the FET (Field-Effect Transistor) device as the generated power brake. In order to reduce heat loss of the FET device, the PWM (Pulse Width Modulation) controller is introduced. Moreover, the experimental system of the proposed method is constituted and the experiment is performed. Finally, the validity and the practicality of the proposed method are confirmed by experimental results.
Improving Road Safety of Tank Truck in Indonesia by Speed Limiter Installation
Pranoto Hadi
2017-01-01
Full Text Available Indonesia has one of the highest number of fatalities caused by traffic accident. It is become main concern since last decades. Approximately of 10% fatalities is caused by tank truck accident, it recorded by PT. Pertamina Persero, Indonesia in 2015 that 17% and 20% tank truck accident is caused by over speed and fatigue, respectively. Therefore, over speed has become main factor the occurrence of tank truck accident. Main objective of this research is to install speed limiter on the tank truck in order to improve safety engineering system, decrease accident and to maintain engine performance. This research is conducted in Indonesia especially in Java-Bali route travel. Speed limiter is installed to the tank truck engine which completed by fuel cut-off solenoid to reduce the speed automatically when it exceeding the maximum speed that has been determined. From the result shows that top speed which performed by driver up to 133 km/h when tank truck uninstalled by speed limiter. Meanwhile, when speed limiter is installed to the tank truck, top speed locked at 70 km/h even though the driver want to speed up. It means that fuel cut-off system is very effective to lock the speed at 70 km/h and it shown the improvement up to 65%. The monitoring activities observed that the decreasing number of fatalities caused by tank truck accident become 7% as compared to last year of 17%. It can be found that the speed limiter coupled by speed recorder was very efficient to improve safety engineering system of the tank truck.
Speed Estimation in Geared Wind Turbines Using the Maximum Correlation Coefficient
Skrimpas, Georgios Alexandros; Marhadi, Kun S.; Jensen, Bogi Bech;
2015-01-01
to overcome the above mentioned issues. The high speed stage shaft angular velocity is calculated based on the maximum correlation coefficient between the 1 st gear mesh frequency of the last gearbox stage and a pure sinus tone of known frequency and phase. The proposed algorithm utilizes vibration signals...
Genetic Analysis of Daily Maximum Milking Speed by a Random Walk Model in Dairy Cows
Karacaören, Burak; Janss, Luc; Kadarmideen, Haja
Data were obtained from dairy cows stationed at research farm ETH Zurich for maximum milking speed. The main aims of this paper are a) to evaluate if the Wood curve is suitable to model mean lactation curve b) to predict longitudinal breeding values by random regression and random walk models...
SU-E-T-444: Gravity Effect On Maximum Leaf Speed in Dynamic IMRT Treatments
Olasolo, J; Pellejero, S; Gracia, M; Gallardo, N; Martin, ML; Lozares, S; Maneru, F; Bragado, L; Miquelez, S [Complejo Hospitalario de Navarra, Pamplona (Spain); Artacho, JM [Universidad de Zaragoza, Zaragoza (Spain)
2015-06-15
Purpose: A leaf sequencing algorithm has been recently developed in our department. Our purpose is to utilize this algorithm to reduce treatment time by studying the feasibility of using several maximum leaf speeds depending on gantry angle and leaf thickness (0.5 or 1 cm at isocenter). To do so, the gravity effect on MLC performance has been examined by means of analysing the dynalog files. Methods: Leaf position errors has been ascertained according to gantry angle and leaf speed in MLC Millenium120 (Varian). In order to do this, the following test has been designed: all leaves move in synchrony, with same speed and 1 cm gap between opposite leaves. This test is implemented for 18 different speeds: 0.25-0.5-0.75-1-1.25-1.5-1.75-2-2.1-2.2-2.3-2.4-2.5-2.6-2.7-2.8-2.9-3.0 cm/s and 8 gantry angles: 0-45-90-135-180-225-270-315. Collimator angle is 2 degrees in all cases since it is the most usual one in IMRT treatments in our department. Dynamic tolerance is 2 mm. Dynalogs files of 10 repetitions of the test are analysed with a Mathlab in-house developed software and RMS error and 95th percentiles are calculated. Varian recommends 2.5 cm/s as the maximum leaf speed for its segmentation algorithm. In our case, we accept this speed in the most restrictive situation: gantry angle 270 and 1 cm leaf thickness. Maximum speeds for the rest of the cases are calculated by keeping the difference between 95th percentile and dynamic tolerance. In this way, beam hold-off probability does not increase. Results: Maximum speeds every 45 degrees of gantry rotation have been calculated for both leaf thickness. These results are 2.9-2.9-2.9-2.9-2.7-2.6-2.6-2.7 cm/s for 0.5 cm leaf thickness and 2.7-2.7-2.7-2.7-2.6-2.5-2.5-2.6 cm/s for 1 cm leaf thickness. Conclusion: Gravity effect on MLC positioning has been studied. Maximum leaf speed according to leaf thickness and gantry angle have been calculated which reduces treatment time.
How fast do living organisms move: Maximum speeds from bacteria to elephants and whales
Meyer-Vernet, Nicole; Rospars, Jean-Pierre
2015-08-01
Despite their variety and complexity, living organisms obey simple scaling laws due to the universality of the laws of physics. In the present paper, we study the scaling between maximum speed and size, from bacteria to the largest mammals. While the preferred speed has been widely studied in the framework of Newtonian mechanics, the maximum speed has rarely attracted the interest of physicists, despite its remarkable scaling property; it is roughly proportional to length throughout nearly the whole range of running and swimming organisms. We propose a simple order-of-magnitude interpretation of this ubiquitous relationship, based on physical properties shared by life forms of very different body structure and varying by more than 20 orders of magnitude in body mass.
Maximum Coronal Mass Ejection Speed as an Indicator of Solar and Geomagnetic Activities
Kilcik, A; Abramenko, V; Goode, P R; Gopalswamy, N; Ozguc, A; Rozelot, J P; 10.1088/0004-637X/727/1/44
2011-01-01
We investigate the relationship between the monthly averaged maximal speeds of coronal mass ejections (CMEs), international sunspot number (ISSN), and the geomagnetic Dst and Ap indices covering the 1996-2008 time interval (solar cycle 23). Our new findings are as follows. (1) There is a noteworthy relationship between monthly averaged maximum CME speeds and sunspot numbers, Ap and Dst indices. Various peculiarities in the monthly Dst index are correlated better with the fine structures in the CME speed profile than that in the ISSN data. (2) Unlike the sunspot numbers, the CME speed index does not exhibit a double peak maximum. Instead, the CME speed profile peaks during the declining phase of solar cycle 23. Similar to the Ap index, both CME speed and the Dst indices lag behind the sunspot numbers by several months. (3) The CME number shows a double peak similar to that seen in the sunspot numbers. The CME occurrence rate remained very high even near the minimum of the solar cycle 23, when both the sunspot ...
Body Fineness Ratio as a Predictor of Maximum Prolonged-Swimming Speed in Coral Reef Fishes
Walker, Jeffrey A.; Alfaro, Michael E.; Noble, Mae M.; Fulton, Christopher J.
2013-01-01
The ability to sustain high swimming speeds is believed to be an important factor affecting resource acquisition in fishes. While we have gained insights into how fin morphology and motion influences swimming performance in coral reef fishes, the role of other traits, such as body shape, remains poorly understood. We explore the ability of two mechanistic models of the causal relationship between body fineness ratio and endurance swimming-performance to predict maximum prolonged-swimming speed (Umax) among 84 fish species from the Great Barrier Reef, Australia. A drag model, based on semi-empirical data on the drag of rigid, submerged bodies of revolution, was applied to species that employ pectoral-fin propulsion with a rigid body at Umax. An alternative model, based on the results of computer simulations of optimal shape in self-propelled undulating bodies, was applied to the species that swim by body-caudal-fin propulsion at Umax. For pectoral-fin swimmers, Umax increased with fineness, and the rate of increase decreased with fineness, as predicted by the drag model. While the mechanistic and statistical models of the relationship between fineness and Umax were very similar, the mechanistic (and statistical) model explained only a small fraction of the variance in Umax. For body-caudal-fin swimmers, we found a non-linear relationship between fineness and Umax, which was largely negative over most of the range of fineness. This pattern fails to support either predictions from the computational models or standard functional interpretations of body shape variation in fishes. Our results suggest that the widespread hypothesis that a more optimal fineness increases endurance-swimming performance via reduced drag should be limited to fishes that swim with rigid bodies. PMID:24204575
Body fineness ratio as a predictor of maximum prolonged-swimming speed in coral reef fishes.
Walker, Jeffrey A; Alfaro, Michael E; Noble, Mae M; Fulton, Christopher J
2013-01-01
The ability to sustain high swimming speeds is believed to be an important factor affecting resource acquisition in fishes. While we have gained insights into how fin morphology and motion influences swimming performance in coral reef fishes, the role of other traits, such as body shape, remains poorly understood. We explore the ability of two mechanistic models of the causal relationship between body fineness ratio and endurance swimming-performance to predict maximum prolonged-swimming speed (Umax ) among 84 fish species from the Great Barrier Reef, Australia. A drag model, based on semi-empirical data on the drag of rigid, submerged bodies of revolution, was applied to species that employ pectoral-fin propulsion with a rigid body at U max. An alternative model, based on the results of computer simulations of optimal shape in self-propelled undulating bodies, was applied to the species that swim by body-caudal-fin propulsion at Umax . For pectoral-fin swimmers, Umax increased with fineness, and the rate of increase decreased with fineness, as predicted by the drag model. While the mechanistic and statistical models of the relationship between fineness and Umax were very similar, the mechanistic (and statistical) model explained only a small fraction of the variance in Umax . For body-caudal-fin swimmers, we found a non-linear relationship between fineness and Umax , which was largely negative over most of the range of fineness. This pattern fails to support either predictions from the computational models or standard functional interpretations of body shape variation in fishes. Our results suggest that the widespread hypothesis that a more optimal fineness increases endurance-swimming performance via reduced drag should be limited to fishes that swim with rigid bodies.
Fundamental Speed Limits to the Generation of Quantumness
Jing, Jun; Wu, Lian-Ao; Del Campo, Adolfo
2016-11-01
Quantum physics dictates fundamental speed limits during time evolution. We present a quantum speed limit governing the generation of nonclassicality and the mutual incompatibility of two states connected by time evolution. This result is used to characterize the timescale required to generate a given amount of quantumness under an arbitrary physical process. The bound is found to be tight under pure dephasing dynamics. More generally, our analysis reveals the dependence on the initial and final states and non-Markovian effects.
SPEED COMPLIANCE IN FREEWAY VARIABLE SPEED LIMIT SYSTEM – CASE STUDY OF THE PRAGUE CITY RING
Michał MATOWICKI
2016-03-01
Full Text Available Many previous studies have confirmed the strong relationship between speed compliance and the frequency and severity of traffic accidents. Variable speed limit (VSL system as a measure to improve traffic safety enables the freeway system to change its posted speed limit based on various traffic and environmental conditions. Such system helps drivers to recognize the upcoming events, to adjust their driving style and in such way to address speed variation of the traffic flow. This is called speed harmonization. Although many studies researching the effect of VSL system on the traffic stream can be found, there are only few addressing its influence on the drivers behavior, particularly focusing on their tolerance limit and compliance, which has crucial meaning for future design of controlling algorithms. This study was prepared to inspect this grey area by studying the data from the VSL system at Prague city ring, describing the influence of the highway management system and its influence on drivers.
OCCURRENCE OF HIGH-SPEED SOLAR WIND STREAMS OVER THE GRAND MODERN MAXIMUM
Mursula, K.; Holappa, L. [ReSoLVE Centre of Excellence, Department of Physics, University of Oulu (Finland); Lukianova, R., E-mail: kalevi.mursula@oulu.fi [Geophysical Center of Russian Academy of Science, Moscow (Russian Federation)
2015-03-01
In the declining phase of the solar cycle (SC), when the new-polarity fields of the solar poles are strengthened by the transport of same-signed magnetic flux from lower latitudes, the polar coronal holes expand and form non-axisymmetric extensions toward the solar equator. These extensions enhance the occurrence of high-speed solar wind (SW) streams (HSS) and related co-rotating interaction regions in the low-latitude heliosphere, and cause moderate, recurrent geomagnetic activity (GA) in the near-Earth space. Here, using a novel definition of GA at high (polar cap) latitudes and the longest record of magnetic observations at a polar cap station, we calculate the annually averaged SW speeds as proxies for the effective annual occurrence of HSS over the whole Grand Modern Maximum (GMM) from 1920s onward. We find that a period of high annual speeds (frequent occurrence of HSS) occurs in the declining phase of each of SCs 16-23. For most cycles the HSS activity clearly reaches a maximum in one year, suggesting that typically only one strong activation leading to a coronal hole extension is responsible for the HSS maximum. We find that the most persistent HSS activity occurred in the declining phase of SC 18. This suggests that cycle 19, which marks the sunspot maximum period of the GMM, was preceded by exceptionally strong polar fields during the previous sunspot minimum. This gives interesting support for the validity of solar dynamo theory during this dramatic period of solar magnetism.
Maximum range of a projectile thrown from constant-speed circular motion
Poljak, Nikola
2016-01-01
The problem of determining the angle at which a point mass launched from ground level with a given speed is a standard exercise in mechanics. Similar, yet conceptually and calculationally more difficult problems have been suggested to improve student proficiency in projectile motion. The problem of determining the maximum distance of a rock thrown from a rotating arm motion is presented and analyzed in detail in this text. The calculational results confirm several conceptually derived conclusions regarding the initial throw position and provide some details on the angles and the way of throwing (underhand or overhand) which produce the maximum throw distance.
IMPACTS OF LOWER SPEED LIMITS IN SOUTH AUSTRALIA
J.E. WOOLLEY
2002-01-01
This paper reports on a more holistic assessment of such schemes taking into account factors in addition to speed and crashes including: traffic volume displacement, physical road network characteristics, environmental factors, community ownership and acceptance, enforcement effort and impact on travel times. The research work has included the analysis of extensive traffic data, community surveys and focus groups, the collection of environmental and travel time data from an instrumented probe vehicle and the computer modelling of road networks. The work reported is based on over 10 years of working with a 40km/h lower urban speed limit area in South Australia. The paper expands the notion of using speed and crash outcomes as the only criteria for measuring the success of lower speed limit schemes.
Theoretical considerations on maximum running speeds for large and small animals.
Fuentes, Mauricio A
2016-02-01
Mechanical equations for fast running speeds are presented and analyzed. One of the equations and its associated model predict that animals tend to experience larger mechanical stresses in their limbs (muscles, tendons and bones) as a result of larger stride lengths, suggesting a structural restriction entailing the existence of an absolute maximum possible stride length. The consequence for big animals is that an increasingly larger body mass implies decreasing maximal speeds, given that the stride frequency generally decreases for increasingly larger animals. Another restriction, acting on small animals, is discussed only in preliminary terms, but it seems safe to assume from previous studies that for a given range of body masses of small animals, those which are bigger are faster. The difference between speed scaling trends for large and small animals implies the existence of a range of intermediate body masses corresponding to the fastest animals.
On the maximum speed of operation of a quantum "black box"
Dugic, M
2001-01-01
We investigate the minimum time needed for (i.e. the maximum speed of) a quantum "black box" ("oracle") operation which employs "quantum parallelism" to be executed. We emphasize that the operation considered employs the quantum-measurement-like establishing of entanglement in the composite system "input register + output register" of a quantum computer's hardware, and we show that the speed of the operation can be increased by increasing the coupling (strength of interaction) in the composite system, as well as by some local operations (e.g., a proper state preparation) performed on the output register. It also proves that the operation employing a macroscopic (or at least a mesoscopic) system to mediate the registers' interaction should be much faster than the operation performed through direct registers' interaction. Finally, we show that adding energy to the composite system needs not to speed up the operation considered. Rather, e.g., in the case of mutually directly interacting registers, the requiremen...
Determining the coating speed limitations for organic photovoltaic inks
Jakubka, Florian; Heyder, Madeleine; Machui, Florian;
2013-01-01
To determine the output capability of present organic photovoltaic (OPV) materials, it is important to know the theoretical maximum coating speeds of the used semiconductor formulations. Here, we present a comprehensive investigation of the coating stability window of several prototype organic...... semiconductor inks relevant for organic solar cells. The coating stability window was first determined experimentally by a sheet to sheet coater at velocities of up to 10 m/min. A numerical simulation model based on the Coating Window Suite 2010 software was established to give insight into the coating......-xylene and tetrahydronaphthalene showed the possibility of coating speeds up to 60 m/min. The simulation further revealed the maximum coating head distances for a given wet film thickness. Finally, we show a solar-cell with slot-die coated PEDOT:PSS and P3HT:PCBM-layer based on the parameters obtained by the simulated data, which...
Structure of Turbulence in Katabatic Flows Below and Above the Wind-Speed Maximum
Grachev, Andrey A.; Leo, Laura S.; Sabatino, Silvana Di; Fernando, Harindra J. S.; Pardyjak, Eric R.; Fairall, Christopher W.
2016-06-01
Measurements of small-scale turbulence made in the atmospheric boundary layer over complex terrain during the Mountain Terrain Atmospheric Modeling and Observations (MATERHORN) Program are used to describe the structure of turbulence in katabatic flows. Turbulent and mean meteorological data were continuously measured on four towers deployed along the east lower slope (2-4°) of Granite Mountain near Salt Lake City in Utah, USA. The multi-level (up to seven) observations made during a 30-day long MATERHORN field campaign in September-October 2012 allowed the study of temporal and spatial structure of katabatic flows in detail, and herein we report turbulence statistics (e.g., fluxes, variances, spectra, and cospectra) and their variations in katabatic flow. Observed vertical profiles show steep gradients near the surface, but in the layer above the slope jet the vertical variability is smaller. It is found that the vertical (normal to the slope) momentum flux and horizontal (along-slope) heat flux in a slope-following coordinate system change their sign below and above the wind maximum of a katabatic flow. The momentum flux is directed downward (upward) whereas the along-slope heat flux is downslope (upslope) below (above) the wind maximum. This suggests that the position of the jet-speed maximum can be obtained by linear interpolation between positive and negative values of the momentum flux (or the along-slope heat flux) to derive the height where the flux becomes zero. It is shown that the standard deviations of all wind-speed components (and therefore of the turbulent kinetic energy) and the dissipation rate of turbulent kinetic energy have a local minimum, whereas the standard deviation of air temperature has an absolute maximum at the height of wind-speed maximum. We report several cases when the destructive effect of vertical heat flux is completely cancelled by the generation of turbulence due to the along-slope heat flux. Turbulence above the wind-speed
Switching speed limitations of high power IGBT modules
Incau, Bogdan Ioan; Trintis, Ionut; Munk-Nielsen, Stig
2015-01-01
In this paper the switching speed limits of high power IGBT modules are investigated. The limitation of turn-on and turn-off switching speeds of the IGBTs are experimentally detected in a pulse tester. Different dc-bus stray inductances are considered, as well as the worst case scenario...... for the blocking dc-link voltage. Switching losses are analyzed upon a considerable variation of resistor value from turn-on gate driver side. Short circuit operations are investigated along with safe operating area for entire module to validate electrical capabilities under extreme conditions....
Maximum relative speeds of living organisms: Why do bacteria perform as fast as ostriches?
Meyer-Vernet, Nicole; Rospars, Jean-Pierre
2016-12-01
Self-locomotion is central to animal behaviour and survival. It is generally analysed by focusing on preferred speeds and gaits under particular biological and physical constraints. In the present paper we focus instead on the maximum speed and we study its order-of-magnitude scaling with body size, from bacteria to the largest terrestrial and aquatic organisms. Using data for about 460 species of various taxonomic groups, we find a maximum relative speed of the order of magnitude of ten body lengths per second over a 1020-fold mass range of running and swimming animals. This result implies a locomotor time scale of the order of one tenth of second, virtually independent on body size, anatomy and locomotion style, whose ubiquity requires an explanation building on basic properties of motile organisms. From first-principle estimates, we relate this generic time scale to other basic biological properties, using in particular the recent generalisation of the muscle specific tension to molecular motors. Finally, we go a step further by relating this time scale to still more basic quantities, as environmental conditions at Earth in addition to fundamental physical and chemical constants.
Speed limit and ramp meter control for traffic flow networks
Goatin, Paola; Göttlich, Simone; Kolb, Oliver
2016-07-01
The control of traffic flow can be related to different applications. In this work, a method to manage variable speed limits combined with coordinated ramp metering within the framework of the Lighthill-Whitham-Richards (LWR) network model is introduced. Following a 'first-discretize-then-optimize' approach, the first order optimality system is derived and the switch of speeds at certain fixed points in time is explained, together with the boundary control for the ramp metering. Sequential quadratic programming methods are used to solve the control problem numerically. For application purposes, experimental setups are presented wherein variable speed limits are used as a traffic guidance system to avoid traffic jams on highway interchanges and on-ramps.
Speed limits for quantum gates in multiqubit systems
Ashhab, S.; De Groot, P.C.; Nori, F.
2012-01-01
We use analytical and numerical calculations to obtain speed limits for various unitary quantum operations in multiqubit systems under typical experimental conditions. The operations that we consider include single-, two-, and three-qubit gates, as well as quantum-state transfer in a chain of qubits
Intelligent Advisory Speed Limit Dedication in Highway Using VANET
Ali Jalooli
2014-01-01
Full Text Available Variable speed limits (VSLs as a mean for enhancing road traffic safety are studied for decades to modify the speed limit based on the prevailing road circumstances. In this study the pros and cons of VSL systems and their effects on traffic controlling efficiency are summarized. Despite the potential effectiveness of utilizing VSLs, we have witnessed that the effectiveness of this system is impacted by factors such as VSL control strategy used and the level of driver compliance. Hence, the proposed approach called Intelligent Advisory Speed Limit Dedication (IASLD as the novel VSL control strategy which considers the driver compliance aims to improve the traffic flow and occupancy of vehicles in addition to amelioration of vehicle’s travel times. The IASLD provides the advisory speed limit for each vehicle exclusively based on the vehicle’s characteristics including the vehicle type, size, and safety capabilities as well as traffic and weather conditions. The proposed approach takes advantage of vehicular ad hoc network (VANET to accelerate its performance, in the way that simulation results demonstrate the reduction of incident detection time up to 31.2% in comparison with traditional VSL strategy. The simulation results similarly indicate the improvement of traffic flow efficiency, occupancy, and travel time in different conditions.
Concerning the maximum frequency limits of Gunn operators
R; F; Macpherson; G; M; Dunn; Ata; Khalid; D; R; S; Cumming
2015-01-01
The length of the transit region of a Gunn diode determines the natural frequency at which it operates in fundamental mode-the shorter the device,the higher the frequency of operation.The long-held view on Gunn diode design is that for a functioning device the minimum length of the transit region is about 1.5μm,limiting the devices to fundamental mode operation at frequencies of roughly 60 GHz.The authors posit that this theoretical restriction is a consequence of limits of the hydrodynamic models by which it was determined.Study of these devices by more advanced Monte Carlo techniques,which simulate the ballistic transport and electron-phonon interactions that govern device behaviour,offers a new lower bound of 0.5μm,which is already being approached by the experimental evidence shown in planar and vertical devices exhibiting Gunn operation at 0.6μm and 0.7μm.It is shown that the limits for Gunn domain operation are determined by the device length required for the transferred electron effect to occur(approximately 0.15μm,which as demonstrated is largely field independent)and the fundamental size of the domain(approximately 0.3μm).At this new length,operation in fundamental mode at much higher frequencies becomes possible-the Monte Carlo model used predicts power output at frequencies over 300 GHz.
Is the Lorentz limiting speed equal to the speed of light? Photons vs neutrino tests
Frere, Jean-Marie; Mollet, Simon; Tytgat, Michel H.G. [Universite Libre de Bruxelles, Service de Physique Theorique, Brussels (Belgium)
2012-11-15
We discuss the possibility that the ''limiting speed'' c{sub limit} (c{sub l}) appearing in Lorentz equations might be different (i.e. slightly larger) than the observed speed of light c{sub n}. We show that such a possibility can be tested by state-of-the-art Michelson-Morley experiments, but also by careful measurement of neutrino speeds. It would indeed suffice to show that c{sub n}
López-Valcarce Roberto
2004-01-01
Full Text Available We address the problem of estimating the speed of a road vehicle from its acoustic signature, recorded by a pair of omnidirectional microphones located next to the road. This choice of sensors is motivated by their nonintrusive nature as well as low installation and maintenance costs. A novel estimation technique is proposed, which is based on the maximum likelihood principle. It directly estimates car speed without any assumptions on the acoustic signal emitted by the vehicle. This has the advantages of bypassing troublesome intermediate delay estimation steps as well as eliminating the need for an accurate yet general enough acoustic traffic model. An analysis of the estimate for narrowband and broadband sources is provided and verified with computer simulations. The estimation algorithm uses a bank of modified crosscorrelators and therefore it is well suited to DSP implementation, performing well with preliminary field data.
Nadhir, Ahmad; Naba, Agus; Hiyama, Takashi
An optimal control for maximizing extraction of power in variable-speed wind energy conversion system is presented. Intelligent gradient detection by fuzzy inference system (FIS) in maximum power point tracking control is proposed to achieve power curve operating near optimal point. Speed rotor reference can be adjusted by maximum power point tracking fuzzy controller (MPPTFC) such that the turbine operates around maximum power. Power curve model can be modelled by using adaptive neuro fuzzy inference system (ANFIS). It is required to simply well estimate just a few number of maximum power points corresponding to optimum generator rotor speed under varying wind speed, implying its training can be done with less effort. Using the trained fuzzy model, some estimated maximum power points as well as their corresponding generator rotor speed and wind speed are determined, from which a linear wind speed feedback controller (LWSFC) capable of producing optimum generator speed can be obtained. Applied to a squirrel-cage induction generator based wind energy conversion system, MPPTFC and LWSFC could maximize extraction of the wind energy, verified by a power coefficient stay at its maximum almost all the time and an actual power line close to a maximum power efficiency line reference.
Claireaux, Guy; Couturier, Christine; Groison, Anne-Laure
2006-09-01
This study is an attempt to gain an integrated understanding of the interactions between temperature, locomotion activity and metabolism in the European sea bass (Dicentrarchus labrax). To our knowledge this study is among the few that have investigated the influence of the seasonal changes in water temperature on swimming performance in fish. Using a Brett-type swim-tunnel respirometer the relationship between oxygen consumption and swimming speed was determined in fish acclimatised to 7, 11, 14, 18, 22, 26 and 30 degrees C. The corresponding maximum swimming speed (U(max)), optimal swimming speed (U(opt)), active (AMR) and standard (SMR) metabolic rates as well as aerobic metabolic scope (MS) were calculated. Using simple mathematical functions, these parameters were modelled as a function of water temperature and swimming speed. Both SMR and AMR were positively related to water temperature up to 24 degrees C. Above 24 degrees C SMR and AMR levelled off and MS tended to decrease. We found a tight relationship between AMR and U(max) and observed that raising the temperature increased AMR and increased swimming ability. However, although fish swam faster at high temperature, the net cost of transport (COT(net)) at a given speed was not influence by the elevation of the water temperature. Although U(opt) doubled between 7 degrees C and 30 degrees C (from 0.3 to 0.6 m s(-1)), metabolic rate at U(opt) represented a relatively constant fraction of the animal active metabolic rate (40-45%). A proposed model integrates the effects of water temperature on the interaction between metabolism and swimming performance. In particular the controlling effect of temperature on AMR is shown to be the key factor limiting maximal swimming speed of sea bass.
75 FR 76482 - Federal Housing Administration (FHA): FHA Maximum Loan Limits for 2011
2010-12-08
... URBAN DEVELOPMENT Federal Housing Administration (FHA): FHA Maximum Loan Limits for 2011 AGENCY: Office...: This notice announces that FHA has posted on its Web site the single-family maximum loan limits for 2011. The loan limit limits can be found at...
Speed limit on the Route de l’Europe
2016-01-01
Construction work to create a cycle path is under way on the Route de l’Europe, between CERN’s Meyrin and Prévessin sites. The new cycle path is expected to be ready for use in August. On the part of the road under construction, only one lane is open and the speed limit is 30 km/h. Unfortunately, drivers frequently exceed this limit. Those who drive too fast put their own lives at risk as well as those of the people working on the site. Please respect the speed limit. In addition, access to the Route de l’Europe from the SM18, SM19 and BA1 areas and from the tunnel may be in the part of the road where only one lane is open. In this case, please join the road only when the traffic lights allow travel in the relevant direction.
Kale, Mehmet; Aşçi, Alper; Bayrak, Coşkun; Açikada, Caner
2009-11-01
The purpose of this study was to investigate the relationships among jumping performances and speed parameters during maximum speed phase in sprinters. Twenty-one men sprinters volunteered to participate at the beginning of the preparation training phase. All tests-including 100-m sprint running, squat jump (SJ), countermovement jump (CMJ), drop jump (DJ), 60-second repetitive jump (RJ), standing long jump (SLJ), standing triple jump (STJ), standing quintuple jump (SQJ), and standing 10-stride jump (STENJ)-were done on switching mats. Flight (FT) and contact times (CT) during the vertical jump tests and 10-m split times during 100-m sprint running were measured by a 2-channel precision timing system (PTS) connected to the mats. The trace marking method was used for measuring the stride length (SL) through 60 m in 100-m sprint running. Stride frequency (SF), maximum velocity (Vmax), jump height for all vertical jumps, and lower-body power in DJ and RJ were calculated. Statistical analysis showed that the highest significant correlation was found between Vmax and DJ height (r = 0.69; p sprint running and SJ (r = 0.39; p sprint running than the other vertical and horizontal jump tests at the beginning of the preparation training phase.
Blazar Jets Push Closer to Cosmic Speed Limit
2005-01-01
Astronomers using the National Science Foundation's Very Long Baseline Array (VLBA) have discovered jets of plasma blasted from the cores of distant galaxies at speeds within one-tenth of one percent of the speed of light, placing these plasma jets among the fastest objects yet seen in the Universe. "This tells us that the physical processes at the cores of these galaxies, called blazars, are extremely energetic and are capable of propelling matter very close to the absolute cosmic speed limit," said Glenn Piner of Whittier College in Whittier, California. Piner, who worked on the project with student Dipesh Bhattari, also of Whittier College, Philip Edwards of the Japan Aerospace Exploration Agency, and Dayton Jones of NASA's Jet Propulsion Laboratory, presented their findings to the American Astronomical Society's meeting in San Diego, California. According to Einstein's Special Theory of Relativity, no object with mass can be accelerated to the speed of light. To get even close to the speed of light requires enormous amounts of energy. "For example, to accelerate a bowling ball to the speed newly measured in these blazars would require all the energy produced in the world for an entire week," Piner said, "and the blobs of plasma in these jets are at least as massive as a large planet". Blazars are active galactic nuclei -- energetic regions surrounding massive black holes at the centers of galaxies. Material being drawn into the black hole forms a spinning disk called an accretion disk. Powerful jets of charged particles are ejected at high speeds along the poles of accretion disks. When these jets happen to be aimed nearly toward the Earth, the objects are called blazars. Taking advantage of the extremely sharp radio "vision" of the continent-wide VLBA, the scientists tracked individual features in the jets of three blazars at distances from Earth ranging from 7.3 to 9 billion light-years. A Boston University team led by Svetlana Jorstad earlier had identified
Speed Control Analysis of Brushless DC Motor Based on Maximum Amplitude DC Current Feedback
Hassan M.A.A.
2014-07-01
Full Text Available This paper describes an approach to develop accurate and simple current controlled modulation technique for brushless DC (BLDC motor drive. The approach is applied to control phase current based on generation of quasi-square wave current by using only one current controller for the three phases. Unlike the vector control method which is complicated to be implemented, this simple current modulation technique presents advantages such as phase currents are kept in balance and the current is controlled through only one dc signal which represent maximum amplitude value of trapezoidal current (Imax. This technique is performed with Proportional Integral (PI control algorithm and triangular carrier comparison method to generate Pulse Width Modulation (PWM signal. In addition, the PI speed controller is incorporated with the current controller to perform desirable speed operation of non-overshoot response. The performance and functionality of the BLDC motor driver are verified via simulation by using MATLAB/SIMULINK. The simulation results show the developed control system performs desirable speed operation of non-overshoot and good current waveforms.
Speed and efficiency limits of multilevel incoherent heat engines
Mukherjee, V.; Niedenzu, W.; Kofman, A. G.; Kurizki, G.
2016-12-01
We present a comprehensive theory of heat engines (HE) based on a quantum-mechanical "working fluid" (WF) with periodically modulated energy levels. The theory is valid for any periodicity of driving Hamiltonians that commute with themselves at all times and do not induce coherence in the WF. Continuous and stroke cycles arise in opposite limits of this theory, which encompasses hitherto unfamiliar cycle forms, dubbed here hybrid cycles. The theory allows us to discover the speed, power, and efficiency limits attainable by incoherently operating multilevel HE depending on the cycle form and the dynamical regimes.
Maximum Entropy Threshold Segmentation for Target Matching Using Speeded-Up Robust Features
Mu Zhou
2014-01-01
Full Text Available This paper proposes a 2-dimensional (2D maximum entropy threshold segmentation (2DMETS based speeded-up robust features (SURF approach for image target matching. First of all, based on the gray level of each pixel and the average gray level of its neighboring pixels, we construct a 2D gray histogram. Second, by the target and background segmentation, we localize the feature points at the interest points which have the local extremum of box filter responses. Third, from the 2D Haar wavelet responses, we generate the 64-dimensional (64D feature point descriptor vectors. Finally, we perform the target matching according to the comparisons of the 64D feature point descriptor vectors. Experimental results show that our proposed approach can effectively enhance the target matching performance, as well as preserving the real-time capacity.
Relationship Between Maximum Aerobic Speed Performance and Distance Covered in Rugby Union Games.
Swaby, Rick; Jones, Paul A; Comfort, Paul
2016-10-01
Swaby, R, Jones, PA, and Comfort, P. Relationship between maximum aerobic speed performance and distance covered in rugby union games. J Strength Cond Res 30(10): 2788-2793, 2016-Researchers have shown a clear relationship between aerobic fitness and the distance covered in professional soccer, although no research has identified such a relationship in rugby union. Therefore, the aim of the study was to identify whether there was a relationship between maximal aerobic speed (MAS) and the distance covered in rugby union games. Fourteen professional rugby union players (age = 26 ± 6 years, height = 1.90 ± 0.12 m, mass = 107.1 ± 24.1 kg) participated in this investigation. Each player performed a MAS test on 3 separate occasions during the preseason, to determine reliability and provide baseline data, and participated in 6 competitive games during the early stages of the season. Game data were collected using global positioning system technology. No significant difference (p > 0.05) in total distance covered was observed between games. Relationships between players' MAS and the average distance covered from 6 competitive games were explored using Pearson's correlation coefficients, with MAS performance showing a strong relationship with distance covered during match play (r = 0.746, p aerobic fitness to increase the distance that the athlete covers in the game.
Phase transition on speed limit traffic with slope
Li Xing-Li; Song Tao; Kuang Hua; Dai Shi-Qiang
2008-01-01
Through introducing a generalized optimal speed function to consider spatial position, slope grade and variable safe headway, the effect of slope in a single-lane highway on the traffic flow is investigated with the extended optimal speed model. The theoretical analysis and simulation results show that the flux of the whole road with the upgrade (or downgrade) increases linearly with density, saturates at a critical density, then maintains this saturated value in a certain density range and finally decreases with density. The value of saturated flux is equal to the maximum flux of the upgrade (or downgrade) without considering the slight influence of the driver's sensitivity. And the fundamental diagrams also depend on sensitivity, slope grade and slope length. The spatiotemporal pattern gives the segregation of different traffic phases caused by the rarefaction wave and the shock wave under a certain initial vehicle number.A comparison between the upgrade and the downgrade indicates that the value of saturated flux of the downgrade is larger than that of the upgrade under the same condition. This result is in accordance with the real traffic.
Raising the Speed Limit for β-Hairpin Formation
Davis, Caitlin M.; Xiao, Shifeng; Raleigh, Daniel P.; Dyer, R. Brian
2012-01-01
Understanding the folding of the β-hairpin is a crucial step in studying how β-rich proteins fold. We have studied CLN025, an optimized ten residue synthetic peptide, which adopts a compact, well-structured β-hairpin conformation. Formation of the component β-sheet and β-turn structures of CLN025 was probed independently using a combination of equilibrium Fourier transform infrared spectroscopy and laser-induced temperature jump coupled with time-resolved infrared and fluorescence spectroscopies. We find that CLN025 is an ultrafast folder due to its small free energy barrier to folding and that it exceeds the predicted speed limit for β-hairpin formation by an order of magnitude. We also find that the folding mechanism cannot be described by a simple two-state model, but rather is a heterogeneous process involving two independent parallel processes. Formation of stabilizing cross-strand hydrophobic interactions and turn alignment occur competitively, with relaxation lifetimes of 82 ± 10 and 124 ± 10 ns, respectively, at the highest probed temperature. The ultrafast and heterogeneous folding kinetics observed for CLN025 provide evidence for folding on a nearly barrierless free energy landscape, and recalibrate the speed limit for the formation of a β-hairpin. PMID:22873643
Chappell, Mark; Odell, Jason
2004-01-01
We measured maximal oxygen consumption (VO(2max)) and burst speed in populations of Trinidadian guppies (Poecilia reticulata) from contrasting high- and low-predation habitats but reared in "common garden" conditions. We tested two hypothesis: first, that predation, which causes rapid life-history evolution in guppies, also impacts locomotor physiology, and second, that trade-offs would occur between burst and aerobic performance. VO(2max) was higher than predicted from allometry, and resting VO(2) was lower than predicted. There were small interdrainage differences in male VO(2max), but predation did not affect VO(2max) in either sex. Maximum burst speed was correlated with size; absolute burst speed was higher in females, but size-adjusted speed was greater in males. For both sexes, burst speed conformed to allometric predictions. There were differences in burst speed between drainages in females, but predation regime did not affect burst speed in either sex. We did not find a significant correlation between burst speed and VO(2max), suggesting no trade-off between these traits. These results indicate that predation-mediated evolution of guppy life history does not produce concomitant evolution in aerobic capacity and maximum burst speed. However, other aspects of swimming performance (response latencies or acceleration) might show adaptive divergence in contrasting predation regimes.
Speed-limited particle-in-cell (SLPIC) simulation
Werner, Gregory; Cary, John; Jenkins, Thomas
2016-10-01
Speed-limited particle-in-cell (SLPIC) simulation is a new method for particle-based plasma simulation that allows increased timesteps in cases where the timestep is determined (e.g., in standard PIC) not by the smallest timescale of interest, but rather by an even smaller physical timescale that affects numerical stability. For example, SLPIC need not resolve the plasma frequency if plasma oscillations do not play a significant role in the simulation; in contrast, standard PIC must usually resolve the plasma frequency to avoid instability. Unlike fluid approaches, SLPIC retains a fully-kinetic description of plasma particles and includes all the same physical phenomena as PIC; in fact, if SLPIC is run with a PIC-compatible timestep, it is identical to PIC. However, unlike PIC, SLPIC can run stably with larger timesteps. SLPIC has been shown to be effective for finding steady-state solutions for 1D collisionless sheath problems, greatly speeding up computation despite a large ion/electron mass ratio. SLPIC is a relatively small modification of standard PIC, with no complexities that might degrade parallel efficiency (compared to PIC), and is similarly compatible with PIC field solvers and boundary conditions.
Lin, Whei-Min; Hong, Chih-Ming [Department of Electrical Engineering, National Sun Yat-Sen University, Kaohsiung 80424 (China)
2010-06-15
To achieve maximum power point tracking (MPPT) for wind power generation systems, the rotational speed of wind turbines should be adjusted in real time according to wind speed. In this paper, a Wilcoxon radial basis function network (WRBFN) with hill-climb searching (HCS) MPPT strategy is proposed for a permanent magnet synchronous generator (PMSG) with a variable-speed wind turbine. A high-performance online training WRBFN using a back-propagation learning algorithm with modified particle swarm optimization (MPSO) regulating controller is designed for a PMSG. The MPSO is adopted in this study to adapt to the learning rates in the back-propagation process of the WRBFN to improve the learning capability. The MPPT strategy locates the system operation points along the maximum power curves based on the dc-link voltage of the inverter, thus avoiding the generator speed detection. (author)
Speed-of-light limitations in passive linear media
Welters, Aaron; Johnson, Steven G
2014-01-01
We prove that well-known speed of light restrictions on electromagnetic energy velocity can be extended to a new level of generality, encompassing even nonlocal chiral media in periodic geometries, while at the same time weakening the underlying assumptions to only passivity and linearity of the medium (either with a transparency window or with dissipation). As was also shown by other authors under more limiting assumptions, passivity alone is sufficient to guarantee causality and positivity of the energy density (with no thermodynamic assumptions). Our proof is general enough to include a very broad range of material properties, including anisotropy, bianisotropy (chirality), nonlocality, dispersion, periodicity, and even delta functions or similar generalized functions. We also show that the "dynamical energy density" used by some previous authors in dissipative media reduces to the standard Brillouin formula for dispersive energy density in a transparency window. The results in this paper are proved by exp...
5 CFR 630.302 - Maximum annual leave accumulation-forty-five day limitation.
2010-01-01
... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Maximum annual leave accumulation-forty-five day limitation. 630.302 Section 630.302 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS ABSENCE AND LEAVE Annual Leave § 630.302 Maximum annual leave...
Fast estimation from above of the maximum wave speed in the Riemann problem for the Euler equations
Guermond, Jean-Luc; Popov, Bojan
2016-09-01
This paper is concerned with the construction of a fast algorithm for computing the maximum speed of propagation in the Riemann solution for the Euler system of gas dynamics with the co-volume equation of state. The novelty in the algorithm is that it stops when a guaranteed upper bound for the maximum speed is reached with a prescribed accuracy. The convergence rate of the algorithm is cubic and the bound is guaranteed for gasses with the co-volume equation of state and the heat capacity ratio γ in the range (1 , 5 / 3 ].
Speeding Up Simulations By Slowing Down Particles: Speed-Limited Particle-In-Cell Simulation
Werner, Gregory R
2015-01-01
Particle-in-cell (PIC) simulation is often impractical for the same reason that it is powerful: it includes too much physics. Sometimes the mere ability to simulate physics on small length or time scales requires those scales to be resolved (by the cell size and timestep) to avoid instability, even when the effects at those scales contribute negligibly to the phenomenon motivating the simulation. For example, a timestep larger than the inverse plasma frequency will often result in unphysical growth of plasma oscillations, even in simulations where plasma oscillations should not arise at all. Larger timesteps are possible in simulations based on reduced physics models, such as MHD or gyrokinetics, or in simulations with implicit time-advances. A new method, speed-limited PIC (SLPIC) simulation, allows larger timesteps without reduced physics and with an explicit time-advance. The SLPIC method slows down fast particles while still accurately representing the particle distribution. SLPIC is valid when fields and...
Tibaek, S; Holmestad-Bechmann, N; Pedersen, Trine B
2015-01-01
OBJECTIVES: To establish reference values for maximum walking speed over 10m for independent community-dwelling Danish adults, aged 60 to 79 years, and to evaluate the effects of gender and age. DESIGN: Cross-sectional study. SETTING: Danish companies and senior citizens clubs. PARTICIPANTS: Two ...
Izawa, Kazuhiro P.; Watanabe, Satoshi; Hirano, Yasuyuki; Matsushima, Shinya; Suzuki, Tomohiro; Oka, Koichiro; Kida, Keisuke; Suzuki, Kengo; Osada, Naohiko; Omiya, Kazuto; Brubaker, Peter H.; Shimizu, Hiroyuki; Akashi, Yoshihiro J.
2015-01-01
Abstract Maximum gait speed and physical activity (PA) relate to mortality and morbidity, but little is known about gender-related differences in these factors in elderly hospitalized cardiac inpatients. This study aimed to determine differences in maximum gait speed and daily measured PA based on sex and the relationship between these measures in elderly cardiac inpatients. A consecutive 268 elderly Japanese cardiac inpatients (mean age, 73.3 years) were enrolled and divided by sex into female (n = 75, 28%) and male (n = 193, 72%) groups. Patient characteristics and maximum gait speed, average step count, and PA energy expenditure (PAEE) in kilocalorie per day for 2 days assessed by accelerometer were compared between groups. Gait speed correlated positively with in-hospital PA measured by average daily step count (r = 0.46, P < 0.001) and average daily PAEE (r = 0.47, P < 0.001) in all patients. After adjustment for left ventricular ejection fraction, step counts and PAEE were significantly lower in females than males (2651.35 ± 1889.92 vs 4037.33 ± 1866.81 steps, P < 0.001; 52.74 ± 51.98 vs 99.33 ± 51.40 kcal, P < 0.001), respectively. Maximum gait speed was slower and PA lower in elderly female versus male inpatients. Minimum gait speed and step count values in this study might be minimum target values for elderly male and female Japanese cardiac inpatients. PMID:25789953
Svendsen, Morten Bo Søndergaard; Domenici, Paolo; Marras, Stefano
2016-01-01
Billfishes are considered to be among the fastest swimmers in the oceans. Previous studies have estimated maximum speed of sailfish and black marlin at around 35 m s(-1) but theoretical work on cavitation predicts that such extreme speed is unlikely. Here we investigated maximum speed of sailfish...
Kim, K. M.; Smetana, P.
1990-03-01
Growth of large diameter Czochralski (CZ) silicon crystals require complete elimination of dislocations by means of Dash technique, where the seed diameter is reduced to a small size typically 3 mm in conjunction with increase in the pull rate. The maximum length of the large CZ silicon is estimated at the fracture stress limit of the seed neck diameter ( d). The maximum lengths for 200 and 300 mm CZ crystals amount to 197 and 87 cm, respectively, with d = 0.3 cm; the estimated maximum weight is 144 kg.
Kordheili, Reza Ahmadi; Bak-Jensen, Birgitte; Pillai, Jayakrishnan Radhakrishna
2014-01-01
High penetration of photovoltaic panels in distribution grid can bring the grid to its operation limits. The main focus of the paper is to determine maximum photovoltaic penetration level in the grid. Three main criteria were investigated for determining maximum penetration level of PV panels...... for this grid: even distribution of PV panels, aggregation of panels at the beginning of each feeder, and aggregation of panels at the end of each feeder. Load modeling is done using Velander formula. Since PV generation is highest in the summer due to irradiation, a summer day was chosen to determine maximum...
Maximum principle and convergence of central schemes based on slope limiters
Mehmetoglu, Orhan
2012-01-01
A maximum principle and convergence of second order central schemes is proven for scalar conservation laws in dimension one. It is well known that to establish a maximum principle a nonlinear piecewise linear reconstruction is needed and a typical choice is the minmod limiter. Unfortunately, this implies that the scheme uses a first order reconstruction at local extrema. The novelty here is that we allow local nonlinear reconstructions which do not reduce to first order at local extrema and still prove maximum principle and convergence. © 2011 American Mathematical Society.
Tønnessen, Espen; Shalfawi, Shaher A I; Haugen, Thomas; Enoksen, Eystein
2011-09-01
The purpose of this study was to examine the effect of 10 weeks' 40-m repeated sprint training program that does not involve strength training on sprinting speed and repeated sprint speed on young elite soccer players. Twenty young well-trained elite male soccer players of age (±SD) 16.4 (±0.9) years, body mass 67.2 (±9.1) kg, and stature 176.3 (±7.4) cm volunteered to participate in this study. All participants were tested on 40-m running speed, 10 × 40-m repeated sprint speed, 20-m acceleration speed, 20-m top speed, countermovement jump (CMJ), and aerobic endurance (beep test). Participants were divided into training group (TG) (n = 10) and control group (CG) (n = 10). The study was conducted in the precompetition phase of the training program for the participants and ended 13 weeks before the start of the season; the duration of the precompetition period was 26 weeks. The TG followed a Periodized repeated sprint training program once a week. The training program consisted of running 40 m with different intensities and duration from week to week. Within-group results indicate that TG had a statistically marked improvement in their performance from pre to posttest in 40-m maximum sprint (-0.06 seconds), 10 × 40-m repeated sprint speed (-0.12 seconds), 20- to 40-m top speed (-0.05 seconds), and CMJ (2.7 cm). The CG showed only a statistically notable improvement from pre to posttest in 10 × 40-m repeated sprint speed (-0.06 seconds). Between-group differences showed a statistically marked improvement for the TG over the CG in 10 × 40-m repeated sprint speed (-0.07 seconds) and 20- to 40-m top speed (-0.05 seconds), but the effect of the improvement was moderate. The results further indicate that a weekly training with repeated sprint gave a moderate but not statistically marked improvement in 40-m sprinting, CMJ, and beep test. The results of this study indicate that the repeated sprint program had a positive effect on several of the parameters tested
Exploring the quantum speed limit with computer games.
Sørensen, Jens Jakob W H; Pedersen, Mads Kock; Munch, Michael; Haikka, Pinja; Jensen, Jesper Halkjær; Planke, Tilo; Andreasen, Morten Ginnerup; Gajdacz, Miroslav; Mølmer, Klaus; Lieberoth, Andreas; Sherson, Jacob F
2016-04-14
Humans routinely solve problems of immense computational complexity by intuitively forming simple, low-dimensional heuristic strategies. Citizen science (or crowd sourcing) is a way of exploiting this ability by presenting scientific research problems to non-experts. 'Gamification'--the application of game elements in a non-game context--is an effective tool with which to enable citizen scientists to provide solutions to research problems. The citizen science games Foldit, EteRNA and EyeWire have been used successfully to study protein and RNA folding and neuron mapping, but so far gamification has not been applied to problems in quantum physics. Here we report on Quantum Moves, an online platform gamifying optimization problems in quantum physics. We show that human players are able to find solutions to difficult problems associated with the task of quantum computing. Players succeed where purely numerical optimization fails, and analyses of their solutions provide insights into the problem of optimization of a more profound and general nature. Using player strategies, we have thus developed a few-parameter heuristic optimization method that efficiently outperforms the most prominent established numerical methods. The numerical complexity associated with time-optimal solutions increases for shorter process durations. To understand this better, we produced a low-dimensional rendering of the optimization landscape. This rendering reveals why traditional optimization methods fail near the quantum speed limit (that is, the shortest process duration with perfect fidelity). Combined analyses of optimization landscapes and heuristic solution strategies may benefit wider classes of optimization problems in quantum physics and beyond.
Exploring the quantum speed limit with computer games
Sørensen, Jens Jakob W. H.; Pedersen, Mads Kock; Munch, Michael; Haikka, Pinja; Jensen, Jesper Halkjær; Planke, Tilo; Andreasen, Morten Ginnerup; Gajdacz, Miroslav; Mølmer, Klaus; Lieberoth, Andreas; Sherson, Jacob F.
2016-04-01
Humans routinely solve problems of immense computational complexity by intuitively forming simple, low-dimensional heuristic strategies. Citizen science (or crowd sourcing) is a way of exploiting this ability by presenting scientific research problems to non-experts. ‘Gamification’—the application of game elements in a non-game context—is an effective tool with which to enable citizen scientists to provide solutions to research problems. The citizen science games Foldit, EteRNA and EyeWire have been used successfully to study protein and RNA folding and neuron mapping, but so far gamification has not been applied to problems in quantum physics. Here we report on Quantum Moves, an online platform gamifying optimization problems in quantum physics. We show that human players are able to find solutions to difficult problems associated with the task of quantum computing. Players succeed where purely numerical optimization fails, and analyses of their solutions provide insights into the problem of optimization of a more profound and general nature. Using player strategies, we have thus developed a few-parameter heuristic optimization method that efficiently outperforms the most prominent established numerical methods. The numerical complexity associated with time-optimal solutions increases for shorter process durations. To understand this better, we produced a low-dimensional rendering of the optimization landscape. This rendering reveals why traditional optimization methods fail near the quantum speed limit (that is, the shortest process duration with perfect fidelity). Combined analyses of optimization landscapes and heuristic solution strategies may benefit wider classes of optimization problems in quantum physics and beyond.
Rannama, Indrek; Port, Kristjan; Bazanov, Boriss
2012-01-01
Maximum gears for youth category riders are limited. As a result, youth category riders are regularly compelled to ride in a high cadence regime. The aim of this study was to investigate if regular work at high cadence regime due to limited transmission in youth category riders reflects in effectual cadence at the point of maximal power generation during the 10 second sprint effort. 24 junior and youth national team cyclist’s average maximal peak power at various cadence regimes was registere...
Probing the Speed Limits of Transmon Dispersive Readout
Walter, Theo; Kurpiers, Philipp; Mondal, Mintu; Pechal, Marek; Wallraff, Andreas
In circuit QED, faster and more accurate measurement of a qubit's state is necessary to achieve better feedback control, to accomplish more complex quantum algorithms and simulations, and to cross the threshold for fault tolerant quantum computing. In this talk, we discuss our experimental progress to minimize the time needed to readout the state of a dispersively coupled transmon qubit with high fidelity. We outline a signal-to-noise ratio model, illuminate the constraints and find optimal parameters for maximizing measurement speed, while maintaining high readout fidelity. Utilizing a Purcell Filter increases the generality of our results as it becomes possible to reach these speeds with a broader set of system parameters.
Improved Reliability of Single-Phase PV Inverters by Limiting the Maximum Feed-in Power
Yang, Yongheng; Wang, Huai; Blaabjerg, Frede
2014-01-01
. The CPG control strategy is activated only when the DC input power from PV panels exceeds a specific power limit. It enables to limit the maximum feed-in power to the electric grids and also to improve the utilization of PV inverters. As a further study, this paper investigates the reliability performance...... of the power devices (e.g. IGBTs) used in PV inverters with the CPG control under different feed-in power limits. A long-term mission profile (i.e. solar irradiance and ambient temperature) based stress analysis approach is extended and applied to obtain the yearly electrical and thermal stresses of the power...
Heidari, Ali; Forouzan, Mohammad R
2013-01-01
Chatter has been recognized as major restriction for the increase in productivity of cold rolling processes, limiting the rolling speed for thin steel strips. It is shown that chatter has close relation with rolling conditions. So the main aim of this paper is to attain the optimum set points of rolling to achieve maximum rolling speed, preventing chatter to occur. Two combination methods were used for optimization. First method is done in four steps: providing a simulation program for chatter analysis, preparing data from simulation program based on central composite design of experiment, developing a statistical model to relate system tendency to chatter and rolling parameters by response surface methodology, and finally optimizing the process by genetic algorithm. Second method has analogous stages. But central composite design of experiment is replaced by Taguchi method and response surface methodology is replaced by neural network method. Also a study on the influence of the rolling parameters on system stability has been carried out. By using these combination methods, new set points were determined and significant improvement achieved in rolling speed.
The effects of disjunct sampling and averaging time on maximum mean wind speeds
Larsén, Xiaoli Guo; Mann, J.
2006-01-01
Conventionally, the 50-year wind is calculated on basis of the annual maxima of consecutive 10-min averages. Very often, however, the averages are saved with a temporal spacing of several hours. We call it disjunct sampling. It may also happen that the wind speeds are averaged over a longer time...... period before being saved. In either case, the extreme wind will be underestimated. This paper investigates the effects of the disjunct sampling interval and the averaging time on the attenuation of the extreme wind estimation by means of a simple theoretical approach as well as measurements...
Sepulveda, C; Dickson, K A
2000-10-01
Tunas (Scombridae) have been assumed to be among the fastest and most efficient swimmers because they elevate the temperature of the slow-twitch, aerobic locomotor muscle above the ambient water temperature (endothermy) and because of their streamlined body shape and use of the thunniform locomotor mode. The purpose of this study was to test the hypothesis that juvenile tunas swim both faster and more efficiently than their ectothermic relatives. The maximum sustainable swimming speed (U(max), the maximum speed attained while using a steady, continuous gait powered by the aerobic myotomal muscle) and the net cost of transport (COT(net)) were compared at 24 degrees C in similar-sized (116-255 mm fork length) juvenile scombrids, an endothermic tuna, the kawakawa (Euthynnus affinis) and the ectothermic chub mackerel (Scomber japonicus). U(max) and COT(net) were measured by forcing individual fish to swim in a temperature-controlled, variable-speed swimming tunnel respirometer. There were no significant interspecific differences in the relationship between U(max) and body mass or fork length or in the relationship between COT(net) and body mass or fork length. Muscle temperatures were elevated by 1.0-2.3 degrees C and 0.1-0.6 degrees C above water temperature in the kawakawa and chub mackerel, respectively. The juvenile kawakawa had significantly higher standard metabolic rates than the chub mackerel, because the total rate of oxygen consumption at a given swimming speed was higher in the kawakawa when the effects of fish size were accounted for. Thus, juvenile kawakawa are not capable of higher sustainable swimming speeds and are not more efficient swimmers than juvenile chub mackerel.
76 FR 78 - Federal Motor Vehicle Safety Standard; Engine Control Module Speed Limiter Device
2011-01-03
... posted speed limit of 55 mph that was in effect in 1991. \\2\\ Comercial Motor Vehicle Speed Control... improved truck designs. \\3\\ Comercial Motor Vehicle Speed Control Devices (1991), DOT HS 807 725. TCA... National Highway Traffic Safety Administration 49 CFR Part 571 Federal Motor Vehicle Safety Standard...
Osterloh, Frank E
2014-10-02
The Shockley-Queisser analysis provides a theoretical limit for the maximum energy conversion efficiency of single junction photovoltaic cells. But besides the semiconductor bandgap no other semiconductor properties are considered in the analysis. Here, we show that the maximum conversion efficiency is limited further by the excited state entropy of the semiconductors. The entropy loss can be estimated with the modified Sackur-Tetrode equation as a function of the curvature of the bands, the degeneracy of states near the band edges, the illumination intensity, the temperature, and the band gap. The application of the second law of thermodynamics to semiconductors provides a simple explanation for the observed high performance of group IV, III-V, and II-VI materials with strong covalent bonding and for the lower efficiency of transition metal oxides containing weakly interacting metal d orbitals. The model also predicts efficient energy conversion with quantum confined and molecular structures in the presence of a light harvesting mechanism.
Hostrup, Morten; Bangsbo, Jens
2016-01-01
Mechanisms underlying fatigue development and limitations for performance during intense exercise have been intensively studied during the past couple of decades. Fatigue development may involve several interacting factors and depends on type of exercise undertaken and training level...... and power output during intense exercise. Regular speed endurance training (SET), i.e. exercise performed at intensities above that corresponding to maximum oxygen consumption (VO2max ), enhances intense exercise performance. However, most of the studies that have provided mechanistic insight...
Biomechanical events in the time to exhaustion at maximum aerobic speed.
Gazeau, F; Koralsztein, J P; Billat, V
1997-10-01
Recent studies reported good intra-individual reproducibility, but great inter-individual variation in a sample of elite athletes, in time to exhaustion (tlim) at the maximal aerobic speed (MAS: the lowest speed that elicits VO2max in an incremental treadmill test). The purpose of the present study was, on the one hand, to detect modifications of kinematic variables at the end of the tlim of the VO2max test and, on the other hand, to evaluate the possibility that such modifications were factors responsible for the inter-individual variability in tlim. Eleven sub-elite male runners (Age = 24 +/- 6 years; VO2max = 69.2 +/- 6.8 ml kg-1 min-1; MAS = 19.2 +/- 1.45 km h-1; tlim = 301.9 +/- 82.7 s) performed two exercise tests on a treadmill (0% slope): an incremental test to determine VO2max and MAS, and an exhaustive constant velocity test to determine tlim at MAS. Statistically significant modifications were noted in several kinematic variables. The maximal angular velocity of knee during flexion was the only variable that was both modified through the tlim test and influenced the exercise duration. A multiple correlation analysis showed that tlim was predicted by the modifications of four variables (R = 0.995, P < 0.01). These variables are directly or indirectly in relation with the energic cost of running. It was concluded that runners who demonstrated stable running styles were able to run longer during MAS test because of optimal motor efficiency.
Maximum Growth Potential and Periods of Resource Limitation in Apple Tree.
Reyes, Francesco; DeJong, Theodore; Franceschi, Pietro; Tagliavini, Massimo; Gianelle, Damiano
2016-01-01
Knowledge of seasonal maximum potential growth rates are important for assessing periods of resource limitations in fruit tree species. In this study we assessed the periods of resource limitation for vegetative (current year stems, and woody biomass) and reproductive (fruit) organs of a major agricultural crop: the apple tree. This was done by comparing relative growth rates (RGRs) of individual organs in trees with reduced competition for resources to trees grown under standard field conditions. Special attention was dedicated to disentangling patterns and values of maximum potential growth for each organ type. The period of resource limitation for vegetative growth was much longer than in another fruit tree species (peach): from late May until harvest. Two periods of resource limitation were highlighted for fruit: from the beginning of the season until mid-June, and about 1 month prior to harvest. By investigating the variability in individual organs growth we identified substantial differences in RGRs among different shoot categories (proleptic and epicormic) and within each group of monitored organs. Qualitatively different and more accurate values of growth rates for vegetative organs, compared to the use of the simple compartmental means, were estimated. Detailed, source-sink based tree growth models, commonly in need of fine parameter tuning, are expected to benefit from the results produced by these analyses.
Backus, George A.; Lowry, Thomas Stephen; Jones, Shannon M; Walker, La Tonya Nicole; Roberts, Barry L; Malczynski, Leonard A.
2017-06-01
This report uses the CMIP5 series of climate model simulations to produce country- level uncertainty distributions for use in socioeconomic risk assessments of climate change impacts. It provides appropriate probability distributions, by month, for 169 countries and autonomous-areas on temperature, precipitation, maximum temperature, maximum wind speed, humidity, runoff, soil moisture and evaporation for the historical period (1976-2005), and for decadal time periods to 2100. It also provides historical and future distributions for the Arctic region on ice concentration, ice thickness, age of ice, and ice ridging in 15-degree longitude arc segments from the Arctic Circle to 80 degrees latitude, plus two polar semicircular regions from 80 to 90 degrees latitude. The uncertainty is meant to describe the lack of knowledge rather than imprecision in the physical simulation because the emphasis is on unfalsified risk and its use to determine potential socioeconom ic impacts. The full report is contained in 27 volumes.
Iammarino, Marco; Di Taranto, Aurelia; Muscarella, Marilena
2012-02-01
Sulphiting agents are commonly used food additives. They are not allowed in fresh meat preparations. In this work, 2250 fresh meat samples were analysed to establish the maximum concentration of sulphites that can be considered as "natural" and therefore be admitted in fresh meat preparations. The analyses were carried out by an optimised Monier-Williams Method and the positive samples confirmed by ion chromatography. Sulphite concentrations higher than the screening method LOQ (10.0 mg · kg(-1)) were found in 100 samples. Concentrations higher than 76.6 mg · kg(-1), attributable to sulphiting agent addition, were registered in 40 samples. Concentrations lower than 41.3 mg · kg(-1) were registered in 60 samples. Taking into account the distribution of sulphite concentrations obtained, it is plausible to estimate a maximum allowable limit of 40.0 mg · kg(-1) (expressed as SO(2)). Below this value the samples can be considered as "compliant".
Structure of Turbulence in Katabatic Flows below and above the Wind-Speed Maximum
Grachev, Andrey A; Di Sabatino, Silvana; Fernando, Harindra J S; Pardyjak, Eric R; Fairall, Christopher W
2015-01-01
Measurements of small-scale turbulence made over the complex-terrain atmospheric boundary layer during the MATERHORN Program are used to describe the structure of turbulence in katabatic flows. Turbulent and mean meteorological data were continuously measured at multiple levels at four towers deployed along the East lower slope (2-4 deg) of Granite Mountain. The multi-level observations made during a 30-day long MATERHORN-Fall field campaign in September-October 2012 allowed studying of temporal and spatial structure of katabatic flows in detail, and herein we report turbulence and their variations in katabatic winds. Observed vertical profiles show steep gradients near the surface, but in the layer above the slope jet the vertical variability is smaller. It is found that the vertical (normal to the slope) momentum flux and horizontal (along the slope) heat flux in a slope-following coordinate system change their sign below and above the wind maximum of a katabatic flow. The vertical momentum flux is directed...
Scaling of wingbeat frequency with body mass in bats and limits to maximum bat size.
Norberg, Ulla M Lindhe; Norberg, R Åke
2012-03-01
The ability to fly opens up ecological opportunities but flight mechanics and muscle energetics impose constraints, one of which is that the maximum body size must be kept below a rather low limit. The muscle power available for flight increases in proportion to flight muscle mass and wingbeat frequency. The maximum wingbeat frequency attainable among increasingly large animals decreases faster than the minimum frequency required, so eventually they coincide, thereby defining the maximum body mass at which the available power just matches up to the power required for sustained aerobic flight. Here, we report new wingbeat frequency data for 27 morphologically diverse bat species representing nine families, and additional data from the literature for another 38 species, together spanning a range from 2.0 to 870 g. For these species, wingbeat frequency decreases with increasing body mass as M(b)(-0.26). We filmed 25 of our 27 species in free flight outdoors, and for these the wingbeat frequency varies as M(b)(-0.30). These exponents are strikingly similar to the body mass dependency M(b)(-0.27) among birds, but the wingbeat frequency is higher in birds than in bats for any given body mass. The downstroke muscle mass is also a larger proportion of the body mass in birds. We applied these empirically based scaling functions for wingbeat frequency in bats to biomechanical theories about how the power required for flight and the power available converge as animal size increases. To this end we estimated the muscle mass-specific power required for the largest flying extant bird (12-16 kg) and assumed that the largest potential bat would exert similar muscle mass-specific power. Given the observed scaling of wingbeat frequency and the proportion of the body mass that is made up by flight muscles in birds and bats, we estimated the maximum potential body mass for bats to be 1.1-2.3 kg. The largest bats, extinct or extant, weigh 1.6 kg. This is within the range expected if it
Dickson, K A; Donley, J M; Hansen, M W; Peters, J A
2012-06-01
Maximum sustained swimming speeds, swimming energetics and swimming kinematics were measured in the green jack Caranx caballus (Teleostei: Carangidae) using a 41 l temperature-controlled, Brett-type swimming-tunnel respirometer. In individual C. caballus [mean ±s.d. of 22·1 ± 2·2 cm fork length (L(F) ), 190 ± 61 g, n = 11] at 27·2 ± 0·7° C, mean critical speed (U(crit)) was 102·5 ± 13·7 cm s⁻¹ or 4·6 ± 0·9 L(F) s⁻¹. The maximum speed that was maintained for a 30 min period while swimming steadily using the slow, oxidative locomotor muscle (U(max,c)) was 99·4 ± 14·4 cm s⁻¹ or 4·5 ± 0·9 L(F) s⁻¹. Oxygen consumption rate (M in mg O₂ min⁻¹) increased with swimming speed and with fish mass, but mass-specific M (mg O₂ kg⁻¹ h⁻¹) as a function of relative speed (L(F) s⁻¹) did not vary significantly with fish size. Mean standard metabolic rate (R(S) ) was 170 ± 38 mg O₂ kg⁻¹ h⁻¹, and the mean ratio of M at U(max,c) to R(S) , an estimate of factorial aerobic scope, was 3·6 ± 1·0. The optimal speed (U(opt) ), at which the gross cost of transport was a minimum of 2·14 J kg⁻¹ m⁻¹, was 3·8 L(F) s⁻¹. In a subset of the fish studied (19·7-22·7 cm L(F) , 106-164 g, n = 5), the swimming kinematic variables of tailbeat frequency, yaw and stride length all increased significantly with swimming speed but not fish size, whereas tailbeat amplitude varied significantly with speed, fish mass and L(F) . The mean propulsive wavelength was 86·7 ± 5·6 %L(F) or 73·7 ± 5·2 %L(T) . Mean ±s.d. yaw and tailbeat amplitude values, calculated from lateral displacement of each intervertebral joint during a complete tailbeat cycle in three C. caballus (19·7, 21·6 and 22·7 cm L(F) ; 23·4, 25·3 and 26·4 cm L(T) ), were 4·6 ± 0·1 and 17·1 ± 2·2 %L(T) , respectively. Overall, the sustained swimming performance, energetics, kinematics, lateral displacement and intervertebral bending angles measured in C. caballus
Improving Road Safety of Tank Truck in Indonesia by Speed Limiter Installation
Pranoto Hadi; Leman A.M; Baba Ishak; Feriyanto Dafit; Putra Gama Widya
2017-01-01
Indonesia has one of the highest number of fatalities caused by traffic accident. It is become main concern since last decades. Approximately of 10% fatalities is caused by tank truck accident, it recorded by PT. Pertamina Persero, Indonesia in 2015 that 17% and 20% tank truck accident is caused by over speed and fatigue, respectively. Therefore, over speed has become main factor the occurrence of tank truck accident. Main objective of this research is to install speed limiter on the tank tru...
Bhuiyan, M. A. E.; Wanik, D. W.; Scerbo, D.; Anagnostou, E. N.
2015-12-01
We have developed a tool, the Convection Risk Index (CRI), to represent the severity, timing and location of convection for select geographic areas. The CRI is calculated from the Convection Risk Matrix (CRM), a tabulation of numerous meteorological parameters which are categorized into four broad factors that contribute to convection (surface and lower level moisture, atmospheric instability, vertical wind shear, and lift); each of these factors have historically been utilized by meteorologists to predict the likelihood for development of thunderstorms. The CRM ascribes a specific threshold value to each parameter in such a way that it creates a unique tool used to calculate the risk for seeing the development of thunderstorms. The parameters were combined using a weighted formula and which when calculated, yields the Convection Risk Index 1 to 4 scale, with 4 being the highest risk for seeing strong convection. In addition, we also evaluated the performance of the parameters in the CRM and CRI for predicting the maximum wind speed in areas where we calculated the CRI using nonparametric tree-based model, Bayesian additive trees (BART). The use of the CRI and the predicted wind speeds from BART can be used to better inform emergency preparedness efforts in government and industry.We have developed a tool, the Convection Risk Index (CRI), to represent the severity, timing and location of convection for select geographic areas. The CRI is calculated from the Convection Risk Matrix (CRM), a tabulation of numerous meteorological parameters which are categorized into four broad factors that contribute to convection (surface and lower level moisture, atmospheric instability, vertical wind shear, and lift); each of these factors have historically been utilized by meteorologists to predict the likelihood for development of thunderstorms. The CRM ascribes a specific threshold value to each parameter in such a way that it creates a unique tool used to calculate the risk for
Hansen, A.D.; Bindner, H. [Risoe National Lab., Wind Energy and Atmospheric Physics Dept., Roskilde (Denmark); Rebsdorf, A. [Vestas Wind Systems A/S, Lem (Denmark)
1999-03-01
The paper summarises and describes the main results of a recently performed study of improving the transition between power optimization and power limitation for variable speed/variable pitch wind turbines. The results show that the capability of varying the generator speed also can be exploited in the transition stage to improve the quality of the generated power. (au)
Change detection in variable speed limits: failed to look or looked but failed to see?
Harms, Ilse M.; Brookhuis, Karel A.
2012-01-01
Variable speed limits (VSL) are used to adjust real-time driver speed to the circumstances of the road condition. Based on theoretical research it has been proposed that change blindness - the failure to detect, identify and localise changes - might play a role in the effectiveness of VSL in terms o
Rotor aerodynamic power limits at low tip speed ratio using CFD
Mikkelsen, Robert Flemming; Sarmast, Sasan; Henningson, Dan;
2014-01-01
. In the present work we study in detail, using a CFD actuator line model, the flow behavior for rotors at small tip speed ratios. It is shown that the excessive swirl appearing towards the rotor center at small tip speed ratios generates vortex breakdown, causing a recirculating zone in the wake that limits...... the power yield of the rotor. The appearance of vortex breakdown has a similar effect on the flow behavior as the vortex ring state that usually appears at higher tip speed ratios. Limits to where vortex breakdown might occur with tip speed ratio and rotor loading as parameter are investigated and presented...... in the paper. The limits found correspond to well-known criterion for vortex breakdown onset for swirling flows in general. By applying a criterion for vortex breakdown in combination with the general momentum theory, the power performance always stays below the Betz limit....
Seymour, Roger S
2010-09-01
Effect of size of inflorescences, flowers and cones on maximum rate of heat production is analysed allometrically in 23 species of thermogenic plants having diverse structures and ranging between 1.8 and 600 g. Total respiration rate (, micromol s(-1)) varies with spadix mass (M, g) according to in 15 species of Araceae. Thermal conductance (C, mW degrees C(-1)) for spadices scales according to C = 18.5M(0.73). Mass does not significantly affect the difference between floral and air temperature. Aroids with exposed appendices with high surface area have high thermal conductance, consistent with the need to vaporize attractive scents. True flowers have significantly lower heat production and thermal conductance, because closed petals retain heat that benefits resident insects. The florets on aroid spadices, either within a floral chamber or spathe, have intermediate thermal conductance, consistent with mixed roles. Mass-specific rates of respiration are variable between species, but reach 900 nmol s(-1) g(-1) in aroid male florets, exceeding rates of all other plants and even most animals. Maximum mass-specific respiration appears to be limited by oxygen delivery through individual cells. Reducing mass-specific respiration may be one selective influence on the evolution of large size of thermogenic flowers.
Dhara, Chirag; Kleidon, Axel
2015-01-01
Convective and radiative cooling are the two principle mechanisms by which the Earth's surface transfers heat into the atmosphere and that shape surface temperature. However, this partitioning is not sufficiently constrained by energy and mass balances alone. We use a simple energy balance model in which convective fluxes and surface temperatures are determined with the additional thermodynamic limit of maximum convective power. We then show that the broad geographic variation of heat fluxes and surface temperatures in the climatological mean compare very well with the ERA-Interim reanalysis over land and ocean. We also show that the estimates depend considerably on the formulation of longwave radiative transfer and that a spatially uniform offset is related to the assumed cold temperature sink at which the heat engine operates.
The research of the maximum wind speed in Tomsk and calculations of dynamic load on antenna systems
Belan, B.; Belan, S.; Romanovskiy, O.; Girshtein, A.; Yanovich, A.; Baidali, S.; Terehov, S.
2017-01-01
The work is concerned with calculations and analysis of the maximum wind speed in Tomsk city. The data for analysis were taken from the TOR-station located in the north-eastern part of the city. The TOR-station sensors to measure a speed and a direction of wind are installed on the 10-meter meteorological mast. Wind is measured by M-63, which uses the standard approach and the program with one-minute averaging for wind gusts recording as well. According to the measured results in the research performed, the estimation of the dynamic and wind load on different types of antenna systems was performed. The work shows the calculations of wind load on ten types of antenna systems, distinguished by their different constructions and antenna areas. For implementation of calculations, we used methods developed in the Central Research and Development Institute of Building Constructions named after V.A. Kucherenko. The research results could be used for design engineering of the static antenna systems and mobile tracking systems for the distant objects.
Limit Distribution Theory for Maximum Likelihood Estimation of a Log-Concave Density.
Balabdaoui, Fadoua; Rufibach, Kaspar; Wellner, Jon A
2009-06-01
We find limiting distributions of the nonparametric maximum likelihood estimator (MLE) of a log-concave density, i.e. a density of the form f(0) = exp varphi(0) where varphi(0) is a concave function on R. Existence, form, characterizations and uniform rates of convergence of the MLE are given by Rufibach (2006) and Dümbgen and Rufibach (2007). The characterization of the log-concave MLE in terms of distribution functions is the same (up to sign) as the characterization of the least squares estimator of a convex density on [0, infinity) as studied by Groeneboom, Jongbloed and Wellner (2001b). We use this connection to show that the limiting distributions of the MLE and its derivative are, under comparable smoothness assumptions, the same (up to sign) as in the convex density estimation problem. In particular, changing the smoothness assumptions of Groeneboom, Jongbloed and Wellner (2001b) slightly by allowing some higher derivatives to vanish at the point of interest, we find that the pointwise limiting distributions depend on the second and third derivatives at 0 of H(k), the "lower invelope" of an integrated Brownian motion process minus a drift term depending on the number of vanishing derivatives of varphi(0) = log f(0) at the point of interest. We also establish the limiting distribution of the resulting estimator of the mode M(f(0)) and establish a new local asymptotic minimax lower bound which shows the optimality of our mode estimator in terms of both rate of convergence and dependence of constants on population values.
CHANGING ATTITUDES OF SPEED-LIMIT OFFENDERS USING A MULTIMEDIA PROGRAM
Frank J.J.M. STEYVERS
2002-01-01
Full Text Available An interactive multimedia computer program was developed to change speed-limit offenders' attitudes with respect to speeding. The computer program is meant to be used during speed controls; the offender may be remitted a part of the fine by completing the program. The objective of the program is to make speeders aware of the negative implications of their behavior and to change their attitude negatively towards offending speed limits. To attain this goal, offenders are confronted with possible negative consequences of speeding while their arguments for speeding are refuted, using small video-clips, demonstrations of counter-arguments and short verbal stories. The effects of this multimedia program were studied in a laboratory evaluation, in terms of knowledge and attitudes, compared with two information conditions, a general leaflet about traffic, and a specific leaflet about speeding. One week after participation in the study subjects were sent a questionnaire, to measure whether changes in knowledge and attitudes were retained afterwards. It appeared that the general attitude towards speeding was changed most in the multimedia program condition, subjects became more negative towards speeding and various related aspects. The specific speeding leaflet appeared to influence the attitude towards driving fun positively and obeying traffic rules negatively, which are unwanted directions. With regard to knowledge of speeding and its consequences the computer program did not do better than the other conditions. However, the subjects considered the program more impressive than the leaflet conditions and indicated that they would consent to participate when being stopped in real speeding conditions.
Time-optimal excitation of maximum quantum coherence: Physical limits and pulse sequences
Köcher, S. S.; Heydenreich, T.; Zhang, Y.; Reddy, G. N. M.; Caldarelli, S.; Yuan, H.; Glaser, S. J.
2016-04-01
Here we study the optimum efficiency of the excitation of maximum quantum (MaxQ) coherence using analytical and numerical methods based on optimal control theory. The theoretical limit of the achievable MaxQ amplitude and the minimum time to achieve this limit are explored for a set of model systems consisting of up to five coupled spins. In addition to arbitrary pulse shapes, two simple pulse sequence families of practical interest are considered in the optimizations. Compared to conventional approaches, substantial gains were found both in terms of the achieved MaxQ amplitude and in pulse sequence durations. For a model system, theoretically predicted gains of a factor of three compared to the conventional pulse sequence were experimentally demonstrated. Motivated by the numerical results, also two novel analytical transfer schemes were found: Compared to conventional approaches based on non-selective pulses and delays, double-quantum coherence in two-spin systems can be created twice as fast using isotropic mixing and hard spin-selective pulses. Also it is proved that in a chain of three weakly coupled spins with the same coupling constants, triple-quantum coherence can be created in a time-optimal fashion using so-called geodesic pulses.
NEW TYPE OF LIMITED-SLIP DIFFERENTIAL WITH THREE-PITCH FLUCTUATING SPEED RATIO
JIANG Hong; WANG Xiaochun
2008-01-01
A type of three-pitch fluctuating speed ratio limited-slip differential (TPLSD) is presented for the first time, analyzed its working principle, introduced the tooth profile design method of using non-involute tooth profile and separated tooth profile design along the pitch line. Performance comparison between vehicles equipped with three-pitch fluctuating speed ratio limited-slip differential and common open differential is finished. The data from experiments prove that three-pitch fluctuating speed ratio limited-slip differential can increase the traction of a vehicle, improve its acceleration performance, decrease braking distance and limit sideslip. The basic structure of new differential is the same of open differential, the only difference is that they have different tooth profile, so the new differential has a high performance price.
Traffic managed? : Why not all drivers can adhere to changes in speed limit signals over the road
Harms, Ilse M.; Brookhuis, Karel A.
2014-01-01
Perceiving changes in variable speed limits is a prerequisite for speed limit compliance. However, under certain circumstances our ability as drivers to detect such changes around us is restrained. Variable speed limits embody traffic management information which drivers regard as very important and
Marczak Monika
2015-09-01
Full Text Available The aim of this study was to determine the correlation between lipophilicity and maximum residue limit (MRL value specified for veterinary drugs in the fatty tissue of various animal species. The analysis was performed on a group of 73 compounds with different modes of action and MRL values determined for the fatty tissue of animals. Additionally, the logarithm of water/organic phase partition ratio (LogP and the ratio of ionised and unionised substance in buffer with pH 7.4 (LogD7.4 were calculated. The main analysis was performed after the division of the whole group into six fractions. The linear correlation and regression analysis were used to determine the indirect relationship between the mean arithmetic value of LogP or LogD7.4 in selected fractions and related LogMRL of the drugs tested. The calculations revealed a linear correlation between fractioned lipophilicity and LogMRL values for the analysed compounds. The existence of indirect relationship between lipophilicity and MRL values determined for fatty tissue was confirmed.
Maximum Parsimony and the Skewness Test: A Simulation Study of the Limits of Applicability
Määttä, Jussi; Roos, Teemu
2016-01-01
The maximum parsimony (MP) method for inferring phylogenies is widely used, but little is known about its limitations in non-asymptotic situations. This study employs large-scale computations with simulated phylogenetic data to estimate the probability that MP succeeds in finding the true phylogeny for up to twelve taxa and 256 characters. The set of candidate phylogenies are taken to be unrooted binary trees; for each simulated data set, the tree lengths of all (2n − 5)!! candidates are computed to evaluate quantities related to the performance of MP, such as the probability of finding the true phylogeny, the probability that the tree with the shortest length is unique, the probability that the true phylogeny has the shortest tree length, and the expected inverse of the number of trees sharing the shortest length. The tree length distributions are also used to evaluate and extend the skewness test of Hillis for distinguishing between random and phylogenetic data. The results indicate, for example, that the critical point after which MP achieves a success probability of at least 0.9 is roughly around 128 characters. The skewness test is found to perform well on simulated data and the study extends its scope to up to twelve taxa. PMID:27035667
Pesticide food safety standards as companions to tolerances and maximum residue limits
Carl K Winter; Elizabeth A Jara
2015-01-01
Alowable levels for pesticide residues in foods, known as tolerances in the US and as maximum residue limits (MRLs) in much of the world, are widely yet inappropriately perceived as levels of safety concern. A novel approach to develop scientiifcaly defensible levels of safety concern is presented and an example to determine acute and chronic pesticide food safety standard (PFSS) levels for the fungicide captan on strawberries is provided. Using this approach, the chronic PFSS level for captan on strawberries was determined to be 2000 mg kg–1 and the acute PFSS level was determined to be 250 mg kg–1. Both levels are far above the existing tolerance and MRLs that commonly range from 3 to 20 mg kg–1, and provide evidence that captan residues detected at levels greater than the tolerance or MRLs are not of acute or chronic health concern even though they represent violative residues. The beneifts of developing the PFSS approach to serve as a companion to existing tolerances/MRLs include a greater understanding concerning the health signiifcance, if any, from exposure to violative pesticide residues. In addition, the PFSS approach can be universaly applied to al potential pesticide residues on al food commodities, can be modiifed by speciifc jurisdictions to take into account differences in food consumption practices, and can help prioritize food residue monitoring by identifying the pesticide/commodity combinations of the greatest potential food safety concern and guiding development of ifeld level analytical methods to detect pesticide residues on prioritized pesticide/commodity combinations.
Josephson, R K; Edman, K A
1998-03-01
1. Isotonic shortening velocities at very light loads were examined in single fibres of the anterior tibialis muscle of the frog, Rana temporaria, using load-clamp recording and slack tests (temperature, 1-3 degrees C; initial sarcomere length, 2.25 microns). 2. Shortening velocities at very light loads (force-clamp recording) were found to be higher early in the rise of a tetanic contraction than during the plateau of the contraction. The upper limit of the load at which there was elevated shortening velocity early in the contraction was 1.5-5.4% of the maximum tetanic tension (Fo) depending on the particular fibre. 3. The maximum shortening velocity determined using the slack test method (Vo) was as much as 30% greater early in a contraction than at the tetanic plateau. Vo was elevated above the plateau level up to about 30 ms after the end of the latent period, which is equivalent to the time required for the force in an isometric contraction to rise to about 30% of Fo. Vo is depressed below the plateau value during relaxation at the cessation of stimulation. 4. Stimulation studies show that the cross-bridge model of Huxley (1957) predicts the maximum shortening velocity to be greater early in a contraction, when new actin binding sites are becoming activated and new cross-bridge connections are being formed rapidly, than during steady-state contraction. The elevated shortening velocity in the model is a consequence of new cross-bridges being formed in the pulling configuration, and there being a delay before the newly added bridges are dragged beyond their equilibrium position so they begin to retard shortening. The model also predicts that maximum shortening velocity should be depressed below the plateau level during early relaxation as cross-bridge binding sites are rapidly removed from the active population.
Kamada, Masamitsu; Kitayuguchi, Jun; Shiwaku, Kuninori; Inoue, Shigeru; Okada, Shimpei; Mutoh, Yoshiteru
2011-08-01
Physical activity contributes to maintaining functional ability later in life. Specific relationships between walking for particular purposes (eg, recreation or transport) and functional ability are not clear. It is useful for planning health promotion strategies to clarify whether walking time for recreation, or walking time for transport has the stronger relationship with maximum walking speed (MWS), a determinant of functional ability later in life in the elderly. A cross-sectional survey was conducted in 2007 using a sample of 372 community-dwelling elderly people aged 60 to 87 years in Mitoya Town, Unnan City, rural Japan. Associations with MWS were examined for self-reported weekly times of walking for recreation and for transport using multiple linear regression analyses. Both in men and women, walking time for recreation was significantly associated with MWS after controlling for age, height, weight, hip and knee pain, and a number of chronic diseases (men: β = 0.18, P = .024; women: β = 0.17, P < .01). However, walking time for transport was not significantly associated with MWS (men: β = -0.094, P = .24; women: β = -0.040, P = .50). Walking for recreation may contribute to maintaining functional abilities such as MWS in the elderly.
Waveless ships in the low speed limit: Results for multi-cornered hulls
Trinh, Philippe H
2015-01-01
In the low-speed limit, a blunt ship modeled as two-dimensional semi-infinite body with a single corner can never be made waveless. This was the conclusion of the previous part of our work in Trinh et al. (2011), which focused on the Dagan & Tulin (1972) model of ship waves in the low speed limit. In this accompanying paper, we continue our investigations with the study of more general, piecewise-linear, or multi-cornered ships. The low-speed or low-Froude limit, coupled with techniques in exponential asymptotics allows us to derive explicit formulae relating the geometry of the hull to the form of the waves. Configurations with closely spaced corners present a non-trivial extension of the theory, and we present the general methodology for their study. Lastly, numerical computations of the nonlinear ship-wave problem are presented in order to confirm the analytical predictions.
Variable speed limit strategies’ analysis with cell transmission model on freeway
Li, Shubin; Cao, Danni
2017-08-01
Mainline freeway traffic flow control is one of the primary methods of traffic management, which can present the best network situation. In this paper, we integrate variable speed limit (VSL) strategy into the cell transmission model (CTM). Then the implementation of the integrated model on freeway traffic network is discussed. A novel optimal model of controlling freeway traffic flow is proposed for minimizing the total travelling time in the network. A solution algorithm is designed by using a simulation method. Considering the main purpose of the speed limit strategy is to control the mainstream flow, we compare the case where the VSL is used with the one without VSL. A simulation is implemented to show that the control strategy is efficient in describing system’s dynamic performance and the dynamic speed limit strategy significantly alleviates congestion.
The Betz-Joukowsky limit for the maximum power coefficient of wind turbines
Okulov, Valery; van Kuik, G.A.M.
2009-01-01
The article addresses to a history of an important scientific result in wind energy. The maximum efficiency of an ideal wind turbine rotor is well known as the ‘Betz limit’, named after the German scientist that formulated this maximum in 1920. Also Lanchester, a British scientist, is associated...
Wegman, F.C.M.
1985-01-01
Advisory speed limits are meant to be used intermittently in situations which are recognised by the road user, while at the same time, not giving a clear suggestion as to the speed which should be sustained. At present advisory speed limits are almost exclusively applied in narrow road curves. Th
Limits on light-speed anisotropies from Compton scattering of high-energy electrons
Bocquet, J -P; Bellini, V; Beretta, M; Casano, L; D'Angelo, A; Di Salvo, R; Fantini, A; Franco, D; Gervino, G; Ghio, F; Giardina, G; Girolami, B; Giusa, A; Gurzadyan, V G; Kashin, A; Knyazyan, S; Lapik, A; Lehnert, R; Sandri, P Levi; Lleres, A; Mammoliti, F; Mandaglio, G; Manganaro, M; Margarian, A; Mehrabyan, S; Messi, R; Nedorezov, V; Perrin, C; Randieri, C; Rebreyend, D; Rudnev, N; Russo, G; Schaerf, C; Sperduto, M L; Sutera, M C; Turinge, A; Vegna, V
2010-01-01
The possibility of anisotropies in the speed of light relative to the limiting speed of electrons is considered. The absence of sidereal variations in the energy of Compton-edge photons at the ESRF's GRAAL facility constrains such anisotropiesrepresenting the first non-threshold collision-kinematics study of Lorentz violation. When interpreted within the minimal Standard-Model Extension,this result yields the two-sided limit of 1.6 x 10^{-14} at 95 % confidence level on a combination of the parity-violating photon and electron coefficients
Morten B. S. Svendsen
2016-10-01
Full Text Available Billfishes are considered to be among the fastest swimmers in the oceans. Previous studies have estimated maximum speed of sailfish and black marlin at around 35 m s−1 but theoretical work on cavitation predicts that such extreme speed is unlikely. Here we investigated maximum speed of sailfish, and three other large marine pelagic predatory fish species, by measuring the twitch contraction time of anaerobic swimming muscle. The highest estimated maximum swimming speeds were found in sailfish (8.3±1.4 m s−1, followed by barracuda (6.2±1.0 m s−1, little tunny (5.6±0.2 m s−1 and dorado (4.0±0.9 m s−1; although size-corrected performance was highest in little tunny and lowest in sailfish. Contrary to previously reported estimates, our results suggest that sailfish are incapable of exceeding swimming speeds of 10-15 m s−1, which corresponds to the speed at which cavitation is predicted to occur, with destructive consequences for fin tissues.
Svendsen, Morten B. S.; Domenici, Paolo; Marras, Stefano; Krause, Jens; Boswell, Kevin M.; Rodriguez-Pinto, Ivan; Wilson, Alexander D. M.; Kurvers, Ralf H. J. M.; Viblanc, Paul E.; Finger, Jean S.; Steffensen, John F.
2016-01-01
ABSTRACT Billfishes are considered to be among the fastest swimmers in the oceans. Previous studies have estimated maximum speed of sailfish and black marlin at around 35 m s−1 but theoretical work on cavitation predicts that such extreme speed is unlikely. Here we investigated maximum speed of sailfish, and three other large marine pelagic predatory fish species, by measuring the twitch contraction time of anaerobic swimming muscle. The highest estimated maximum swimming speeds were found in sailfish (8.3±1.4 m s−1), followed by barracuda (6.2±1.0 m s−1), little tunny (5.6±0.2 m s−1) and dorado (4.0±0.9 m s−1); although size-corrected performance was highest in little tunny and lowest in sailfish. Contrary to previously reported estimates, our results suggest that sailfish are incapable of exceeding swimming speeds of 10-15 m s−1, which corresponds to the speed at which cavitation is predicted to occur, with destructive consequences for fin tissues. PMID:27543056
Maximum detection range limitation of pulse laser radar with Geiger-mode avalanche photodiode array
Luo, Hanjun; Xu, Benlian; Xu, Huigang; Chen, Jingbo; Fu, Yadan
2015-05-01
When designing and evaluating the performance of laser radar system, maximum detection range achievable is an essential parameter. The purpose of this paper is to propose a theoretical model of maximum detection range for simulating the Geiger-mode laser radar's ranging performance. Based on the laser radar equation and the requirement of the minimum acceptable detection probability, and assuming the primary electrons triggered by the echo photons obey Poisson statistics, the maximum range theoretical model is established. By using the system design parameters, the influence of five main factors, namely emitted pulse energy, noise, echo position, atmospheric attenuation coefficient, and target reflectivity on the maximum detection range are investigated. The results show that stronger emitted pulse energy, lower noise level, more front echo position in the range gate, higher atmospheric attenuation coefficient, and higher target reflectivity can result in greater maximum detection range. It is also shown that it's important to select the minimum acceptable detection probability, which is equivalent to the system signal-to-noise ratio for producing greater maximum detection range and lower false-alarm probability.
49 CFR 213.307 - Class of track: operating speed limits.
2010-10-01
... hazardous material, as defined at 49 CFR 171.8, except as provided in Column 9A of the Hazardous Materials Table (49 CFR 172.101) for movement in the same train as a passenger-carrying vehicle or in Column 9B of... 49 Transportation 4 2010-10-01 2010-10-01 false Class of track: operating speed limits....
Development of an algorithm for using weather-dependent dynamic speed limits to enhance safety
Jonkers, E.; Klunder, G.; Horst, A.R.A. van der; Rooy, R. de
2008-01-01
This paper describes an ongoing research project in the Netherlands for lowering the speed limit, depending on the weather condition (in particular rain) to enhance traffic safety. The research in this project consists of three main parts. In the first part, research has been conducted on the strate
Elastic limit angular speed of solid and annular disks under thermo ...
Prof. Kashi Nath Sah
loading and accounted for in dimensional mode as limit peripheral speed and ... elastic plastic material having a state of plane stress. .... On substitution of equations (3) and (6) in the energy principle (. ) ,0. VU. =+ δ .... indicates differentiation with respect to normalized coordinate .ξ Equation (12) can be expressed as [ ]{} {}f.
Limit speed of particles in a non-homogeneous electric field under friction
Diaz-Cano, A [Departamento de Algebra, Facultad de CC. Matematicas, UCM (Spain); Gonzalez-Gascon, F [Departamento de Fisica Teorica II, Facultad de CC. Fisicas, UCM (Spain)
2007-12-14
It is shown that under certain conditions the limit speed of electric charges moving in a space of type R{sup n} of dimension one or two, under isotropic friction, is preserved under some perturbations. These results hold when relativistic equations of motion are considered.
Dynamic traffic management on a familiar road : Failing to detect changes in variable speed limits
Harms, Ilse M.; Brookhuis, Karel A.
2016-01-01
Variable speed limits (VSL) are used more commonly around the globe lately. Although on a macroscopic level positive effects of VSLs have been reported, the caveat is that the impact of VSLs is very sensitive to the level of driver compliance. Thus far it is unknown whether all individual drivers ar
2012-01-01
We describe herein, limitations on research at biosafety level 4 (BSL-4) containment laboratories, with regard to biosecurity regulations, safety considerations, research space limitations, and physical constraints in executing experimental procedures. These limitations can severely impact the number of collaborations and size of research projects investigating microbial pathogens of biodefense concern. Acquisition, use, storage, and transfer of biological select agents and toxins (BSAT) are ...
Özgüç, A; Georgieva, K; Kirov, B
2016-01-01
On the basis of morphological analysis of yearly values of the maximum CME (coronal mass ejection) speed index, the sunspot number and total sunspot area, sunspot magnetic field, and solar flare index, the solar wind speed and interplanetary magnetic field strength, and the geomagnetic Ap and Dst indices, we point out the particularities of solar and geomagnetic activity during the last cycle 23, the long minimum which followed it and the ascending branch of cycle 24. We also analyze temporal offset between the maximum CME speed index and the above-mentioned solar, geomagnetic, and interplanetary indices. It is found that this solar activity index, analyzed jointly with other solar activity, interplanetary parameters, and geomagnetic activity indices, shows a hysteresis phenomenon. It is observed that these parameters follow different paths for the ascending and the descending phases of solar cycle 23. It is noticed that the hysteresis phenomenon represents a clue in the search for physical processes responsi...
SELECTED PARAMETERS OF THE WORK OF SPEED LIMITER IN LINE STRAINING SYSTEM IN A FRICTIONAL LIFT
Paweł Lonkwic
2014-03-01
Full Text Available The article presents the analysis of selected work parameters of speed limiter in line straining system. We analyzed the effect of changing the geometrical conditions of the new solution for the speed limiter in line straining system upon the working conditions in frictional lift braking system. Within the conducted simulations of the work of the system, which is responsible for lift braking with a tension with spring, a test bed was prepared, which simulated the work of tension-rope-limiter system. The tests were performed in the conditions reflecting the work of a lifting appliance. Analyzing the results obtained through empirical calculations, we can conclude that there is a possibility of applying the spring to eliminate the weight.
Some limitations in applying classical EHD film-thickness formulae to a high-speed bearing
Coy, J. J.; Zaretsky, E. V.
1980-01-01
Elastohydrodynamic film thickness was measured for a 20 mm ball bearing using the capacitance technique. The bearing was thrust loaded to 90, 448, and 778 N. The corresponding maximum stresses on the inner race were 1.28, 2.09, and 2.45 GPa. Test speeds ranged from 400 to 14,000 rpm. Film thickness measurements were taken with four different lubricants: (1) synthetic paraffinic; (2) synthetic paraffinic with additives; (3) neopentylpolyol (tetra) ester; and (4) synthetic cycloaliphatic hydrocarbon traction fluid. The test bearing was mist lubricated. Test temperatures were 300, 338, and 393 K. The measured results were compared to theoretical predictions and are presented.
Phongphan Tankasem
2015-06-01
Full Text Available The objective of this study is to evaluate the speed control measure on the arterial road of Khon Kaen city. The 60 km/hr speed limit was posted on the urban arterial since 2012. To reveal the existing conditions, this study analyzed the accident data, speed data and enforcement data. Driver’s and government officer’s attitudes toward the existing speed control measures are captured through the questionnaires survey and interview processes, respectively. The study results reveal that under the existing road environment, the drivers disagree with the posted 60 km/h speed limit and it cannot be enforced by the police. However, 1-year of speed control program significantly reduces the number of traffic injuries and fatalities. Spot speed study revealed that most of drivers reduced their speed once they saw the police with the radar gun. 86% of drivers agree with the speed control measure and 93% of drivers aware that driving speed is related to safety. Therefore, to support the existing speed control measure, this study suggests that the responsible authorities should consider and study for the suitable speed limit for the area and modify the road geometries accordingly. Besides, installing automatic speed enforcement devices, and continuing public campaign directly to the risk groups could also increase the effectiveness of the program.
Shurtleff, Amy C; Garza, Nicole; Lackemeyer, Matthew; Carrion, Ricardo; Griffiths, Anthony; Patterson, Jean; Edwin, Samuel S; Bavari, Sina
2012-12-01
We describe herein, limitations on research at biosafety level 4 (BSL-4) containment laboratories, with regard to biosecurity regulations, safety considerations, research space limitations, and physical constraints in executing experimental procedures. These limitations can severely impact the number of collaborations and size of research projects investigating microbial pathogens of biodefense concern. Acquisition, use, storage, and transfer of biological select agents and toxins (BSAT) are highly regulated due to their potential to pose a severe threat to public health and safety. All federal, state, city, and local regulations must be followed to obtain and maintain registration for the institution to conduct research involving BSAT. These include initial screening and continuous monitoring of personnel, controlled access to containment laboratories, accurate and current BSAT inventory records. Safety considerations are paramount in BSL-4 containment laboratories while considering the types of research tools, workflow and time required for conducting both in vivo and in vitro experiments in limited space. Required use of a positive-pressure encapsulating suit imposes tremendous physical limitations on the researcher. Successful mitigation of these constraints requires additional time, effort, good communication, and creative solutions. Test and evaluation of novel vaccines and therapeutics conducted under good laboratory practice (GLP) conditions for FDA approval are prioritized and frequently share the same physical space with important ongoing basic research studies. The possibilities and limitations of biomedical research involving microbial pathogens of biodefense concern in BSL-4 containment laboratories are explored in this review.
Jean Patterson
2012-12-01
Full Text Available We describe herein, limitations on research at biosafety level 4 (BSL-4 containment laboratories, with regard to biosecurity regulations, safety considerations, research space limitations, and physical constraints in executing experimental procedures. These limitations can severely impact the number of collaborations and size of research projects investigating microbial pathogens of biodefense concern. Acquisition, use, storage, and transfer of biological select agents and toxins (BSAT are highly regulated due to their potential to pose a severe threat to public health and safety. All federal, state, city, and local regulations must be followed to obtain and maintain registration for the institution to conduct research involving BSAT. These include initial screening and continuous monitoring of personnel, controlled access to containment laboratories, accurate and current BSAT inventory records. Safety considerations are paramount in BSL-4 containment laboratories while considering the types of research tools, workflow and time required for conducting both in vivo and in vitro experiments in limited space. Required use of a positive-pressure encapsulating suit imposes tremendous physical limitations on the researcher. Successful mitigation of these constraints requires additional time, effort, good communication, and creative solutions. Test and evaluation of novel vaccines and therapeutics conducted under good laboratory practice (GLP conditions for FDA approval are prioritized and frequently share the same physical space with important ongoing basic research studies. The possibilities and limitations of biomedical research involving microbial pathogens of biodefense concern in BSL-4 containment laboratories are explored in this review.
Limits on light-speed anisotropies from Compton scattering of high-energy electrons.
Bocquet, J-P; Moricciani, D; Bellini, V; Beretta, M; Casano, L; D'Angelo, A; Di Salvo, R; Fantini, A; Franco, D; Gervino, G; Ghio, F; Giardina, G; Girolami, B; Giusa, A; Gurzadyan, V G; Kashin, A; Knyazyan, S; Lapik, A; Lehnert, R; Levi Sandri, P; Lleres, A; Mammoliti, F; Mandaglio, G; Manganaro, M; Margarian, A; Mehrabyan, S; Messi, R; Nedorezov, V; Perrin, C; Randieri, C; Rebreyend, D; Rudnev, N; Russo, G; Schaerf, C; Sperduto, M L; Sutera, M C; Turinge, A; Vegna, V
2010-06-18
The possibility of anisotropies in the speed of light relative to the limiting speed of electrons is considered. The absence of sidereal variations in the energy of Compton-edge photons at the European Synchrotron Radiation Facility's GRAAL facility constrains such anisotropies representing the first nonthreshold collision-kinematics study of Lorentz violation. When interpreted within the minimal standard-model extension, this result yields the two-sided limit of 1.6×10(-14) at 95% confidence level on a combination of the parity-violating photon and electron coefficients (κ(o+))(YZ), (κ(o+))(ZX), c(TX), and c(TY). This new constraint provides an improvement over previous bounds by 1 order of magnitude.
Integrated Variable Speed Limits Control and Ramp Metering for Bottleneck Regions on Freeway
Ming-hui Ma
2015-01-01
Full Text Available To enhance the efficiency of the existing freeway system and therefore to mitigate traffic congestion and related problems on the freeway mainline lane-drop bottleneck region, the advanced strategy for bottleneck control is essential. This paper proposes a method that integrates variable speed limits and ramp metering for freeway bottleneck region control to relieve the chaos in bottleneck region. To this end, based on the analyses of spatial-temporal patterns of traffic flow, a macroscopic traffic flow model is extended to describe the traffic flow operating characteristic by considering the impacts of variable speed limits in mainstream bottleneck region. In addition, to achieve the goal of balancing the priority of the vehicles on mainline and on-ramp, increasing capacity, and reducing travel delay on bottleneck region, an improved control model, as well as an advanced control strategy that integrates variable speed limits and ramp metering, is developed. The proposed method is tested in simulation for a real freeway infrastructure feed and calibrates real traffic variables. The results demonstrate that the proposed method can substantially improve the traffic flow efficiency of mainline and on-ramp and enhance the quality of traffic flow at the investigated freeway mainline bottleneck.
Balance impairment limits ability to increase walking speed in individuals with chronic stroke.
Middleton, Addie; Braun, Carty H; Lewek, Michael D; Fritz, Stacy L
2017-03-01
Purpose Determine the relationship between balance impairments and the ability to increase walking speed (WS) on demand in individuals with chronic stroke. Methods WS and Berg Balance Scale (BBS) data were collected on 124 individuals with chronic stroke (>6 months). The ability to increase WS on demand (walking speed reserve, WSR) was quantified as the difference between participants' self-selected (SSWS) and maximal (MWS) walking speeds. Correlation, regression and receiver operating characteristic (ROC) analyses were performed to investigate the relationship between balance and the ability to increase WS. Results Of sample, 58.9% were unable to increase WS on demand (WSR increase WS [odds ratio (OR) = 0.75, 0.67-0.84]. The AUC for the ROC curve constructed to assess the accuracy of BBS to discriminate between able/unable to increase WS was 0.85 (0.78-0.92). A BBS cutscore of 47 points was identified [sensitivity: 72.6%, specificity: 90.2%, +likelihood ratio (LR): 7.41, -LR: 0.30]. Conclusions The inability to increase WS on demand is common in individuals with chronic stroke, and balance appears to be a significant contributor to this difficulty. A BBS cutscore of 47 points can identify individuals who may benefit from balance interventions to improve the ability to increase their WS. Implications for Rehabilitation A majority of individuals with chronic stroke may be unable to increase their walking speed beyond their self-selected speed on demand. This may limit functional ambulation, as these individuals are walking "at capacity". Balance impairments contribute to the inability to increase walking speed. A Berg Balance Scale score <47 points can be used to identify individuals with chronic stroke walking "at capacity" due to balance impairments.
Jing Cao
2015-06-01
Full Text Available Over the past few decades, urban freeway congestion has been highly recognized as a serious and worsening traffic problem in the world. To relieve freeway congestion, several active traffic and demand management (ATDM methods have been developed. Among them, variable speed limit (VSL aims at regulating freeway mainline flow upstream to meet existing capacity and to harmonize vehicle speed. However, congestion may still be inevitable even with VSL implemented due to extremely high demand in actual practice. This study modified an existing VSL strategy by adding a new local constraint to suggest an achievable speed limit during the control period. As a queue is a product of the congestion phenomenon in freeway, the incentives of a queue build-up in the applied coordinated VSL control situation were analyzed. Considering a congestion occurrence (a queue build-up characterized by a sudden and sharp speed drop, speed contours were utilized to demonstrate the congestion distribution over a whole freeway network in various scenarios. Finally, congestion distributions found in both VSL control and non-VS control situations for various scenarios were investigated to explore the impact of the applied coordinated VSL control on the congestion distribution. An authentic stretch of Whitemud Drive (WMD, an urban freeway corridor in Edmonton, Alberta, Canada, was employed to implement this modified coordinated VSL control strategy; and a calibrated micro-simulation VISSIM model (model functions was applied as the substitute of the real-world traffic system to test the above mentioned performance. The exploration task in this study can lay the groundwork for future research on how to improve the presented VSL control strategy for achieving the congestion mitigation effect on freeway.
Maximum acceptable inherent buoyancy limit for aircrew/passenger helicopter immersion suit systems.
Brooks, C J
1988-12-01
Helicopter crew and passengers flying over cold water wear immersion suits to provide hypothermic protection in case of ditching in cold water. The suits and linings have trapped air in the material to provide the necessary insulation and are thus very buoyant. By paradox, this buoyancy may be too much for a survivor to overcome in escaping from the cabin of a rapidly sinking inverted helicopter. The Canadian General Standard Board requested that research be conducted to investigate what should be the maximum inherent buoyancy in an immersion suit that would not inhibit escape, yet would provide adequate thermal insulation. This experiment reports on 12 subjects who safely escaped with 146N (33 lbf) of added buoyancy from a helicopter underwater escape trainer. It discusses the logic for and recommendation that the inherent buoyancy in a helicopter crew/passenger immersion suit system should not exceed this figure.
Maximum precision closed-form solution for localizing diffraction-limited spots in noisy images.
Larkin, Joshua D; Cook, Peter R
2012-07-30
Super-resolution techniques like PALM and STORM require accurate localization of single fluorophores detected using a CCD. Popular localization algorithms inefficiently assume each photon registered by a pixel can only come from an area in the specimen corresponding to that pixel (not from neighboring areas), before iteratively (slowly) fitting a Gaussian to pixel intensity; they fail with noisy images. We present an alternative; a probability distribution extending over many pixels is assigned to each photon, and independent distributions are joined to describe emitter location. We compare algorithms, and recommend which serves best under different conditions. At low signal-to-noise ratios, ours is 2-fold more precise than others, and 2 orders of magnitude faster; at high ratios, it closely approximates the maximum likelihood estimate.
L1 Adaptive Speed Control of a Small Wind Energy Conversion System for Maximum Power Point Tracking
Zhao, Haoran; Wu, Qiuwei; Rasmussen, Claus Nygaard;
2014-01-01
speed estimation. The proposed MPPT control algorithm has a generic structure and can be used for different generator types. In order to verify the efficacy of the proposed L1 adaptive controller for the MPPT of the WECS, a full converter wind turbine with a squirrel cage induction generator (SCIG...
Svendsen, Morten B S; Domenici, Paolo; Marras, Stefano;
2016-01-01
, and three other large marine pelagic predatory fish species, by measuring the twitch contraction time of anaerobic swimming muscle. The highest estimated maximum swimming speeds were found in sailfish (8.3±1.4 m s(-1)), followed by barracuda (6.2±1.0 m s(-1)), little tunny (5.6±0.2 m s(-1)) and dorado (4...
Gutierrez-Jurado, H. A.; Guan, H.; Wang, J.; Wang, H.; Bras, R. L.; Simmons, C. T.
2015-12-01
Quantification of evapotranspiration (ET) and its partition over regions of heterogeneous topography and canopy poses a challenge using traditional approaches. In this study, we report the results of a novel field experiment design guided by the Maximum Entropy Production model of ET (MEP-ET), formulated for estimating evaporation and transpiration from homogeneous soil and canopy. A catchment with complex terrain and patchy vegetation in South Australia was instrumented to measure temperature, humidity and net radiation at soil and canopy surfaces. Performance of the MEP-ET model to quantify transpiration and soil evaporation was evaluated during wet and dry conditions with independently and directly measured transpiration from sapflow and soil evaporation using the Bowen Ratio Energy Balance (BREB). MEP-ET transpiration shows remarkable agreement with that obtained through sapflow measurements during wet conditions, but consistently overestimates the flux during dry periods. However, an additional term introduced to the original MEP-ET model accounting for higher stomatal regulation during dry spells, based on differences between leaf and air vapor pressure deficits and temperatures, significantly improves the model performance. On the other hand, MEP-ET soil evaporation is in good agreement with that from BREB regardless of moisture conditions. The experimental design allows a plot and tree scale quantification of evaporation and transpiration respectively. This study confirms for the first time that the MEP-ET originally developed for homogeneous open bare soil and closed canopy can be used for modeling ET over heterogeneous land surfaces. Furthermore, we show that with the addition of an empirical function simulating the plants ability to regulate transpiration, and based on the same measurements of temperature and humidity, the method can produce reliable estimates of ET during both wet and dry conditions without compromising its parsimony.
Zile, M R; Izzi, G; Gaasch, W H
1991-02-01
We tested the hypothesis that maximum systolic elastance (Emax) fails to detect a decline in left ventricular (LV) contractile function when diastolic dysfunction is present. Canine hearts were studied in an isolated blood-perfused heart apparatus (isovolumic LV); contractile dysfunction was produced by 60 or 90 minutes of global ischemia, followed by 90 minutes of reperfusion. Nine normal hearts underwent 60 minutes of ischemia, and five underwent 90 minutes of ischemia. After the ischemia-reperfusion sequence, developed pressure, pressure-volume area, and myocardial ATP level were significantly less than those at baseline in all 14 hearts. In the group undergoing 60 minutes of ischemia, LV diastolic pressure did not increase, whereas Emax decreased from 5.2 +/- 2.5 to 2.9 +/- 1.4 mm Hg/ml (p less than 0.05). In the group undergoing 90 minutes of ischemia, diastolic pressure increased (from 10 +/- 2 to 37 +/- 20 mm Hg, p less than 0.05), and Emax did not change significantly (from 5.1 +/- 4.3 to 4.3 +/- 2.5 mm Hg/ml). A second series of experiments was performed in 13 hearts with pressure-overload hypertrophy (aortic-band model with echocardiography and catheterization studies before the ischemia-reperfusion protocol). Five had evidence for pump failure, whereas eight remained compensated. After 60 minutes of ischemia and 90 minutes of reperfusion, developed pressure, pressure-volume area, and myocardial ATP level were significantly less than those at baseline in all 13 hearts. In the group with compensated LV hypertrophy, LV diastolic pressure did not change, whereas Emax decreased from 6.9 +/- 3.0 to 3.1 +/- 2.3 mm Hg/ml (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
李志斌; 刘攀; 王炜; 徐铖铖
2014-01-01
A control strategy of variable speed limits (VSL) was developed to reduce the travel time at freeway recurrent bottleneck areas. The proposed control strategy particularly focused on preventing the capacity drop and increasing the discharge flow. A cell transmission model (CTM) was developed to evaluate the effects of the proposed VSL control strategy on the traffic operations. The results show that the total travel time is reduced by 25.5% and the delay is reduced by 56.1%. The average travel speed is increased by 34.3% and the queue length is reduced by 31.0%. The traffic operation is improved by the proposed VSL control strategy. The way to use the proposed VSL control strategy in different types of freeway bottlenecks was also discussed by considering different traffic flow characteristics. It is concluded that the VSL control strategy is effective for merge bottlenecks but is less effective for diverge bottlenecks.
No speed limits in medical imaging and high-energy physics
Rita Giuffredi & Tom Meyer
2015-01-01
Speed, or high time resolution, is becoming increasingly important, if not crucial, in the high-energy physics domain, both for particle acceleration and detection systems. Medical-imaging technology also vitally depends on high time resolution detection techniques, often the offspring of today’s large particle physics experiments. The four-year FP7 Marie Curie Training Project “PicoSEC-MCNet”, which draws to a close at the end of November, was designed to develop ultra-fast photon detectors for applications in both domains. The project has achieved important results that promise to trigger further developments in the years to come. The PicoSEC-MCNet project participants. “New requirements in high-energy physics force us to push the limits of photon detection speed, as future high-luminosity accelerators will force us to cope with the unprecedentedly short bunch crossing intervals needed to produce sufficient luminosity,” explains Tom M...
A limit on the variation of the speed of light arising from quantum gravity effects.
Abdo, A A; Ackermann, M; Ajello, M; Asano, K; Atwood, W B; Axelsson, M; Baldini, L; Ballet, J; Barbiellini, G; Baring, M G; Bastieri, D; Bechtol, K; Bellazzini, R; Berenji, B; Bhat, P N; Bissaldi, E; Bloom, E D; Bonamente, E; Bonnell, J; Borgland, A W; Bouvier, A; Bregeon, J; Brez, A; Briggs, M S; Brigida, M; Bruel, P; Burgess, J M; Burnett, T H; Caliandro, G A; Cameron, R A; Caraveo, P A; Casandjian, J M; Cecchi, C; Celik, O; Chaplin, V; Charles, E; Cheung, C C; Chiang, J; Ciprini, S; Claus, R; Cohen-Tanugi, J; Cominsky, L R; Connaughton, V; Conrad, J; Cutini, S; Dermer, C D; de Angelis, A; de Palma, F; Digel, S W; Dingus, B L; do Couto E Silva, E; Drell, P S; Dubois, R; Dumora, D; Farnier, C; Favuzzi, C; Fegan, S J; Finke, J; Fishman, G; Focke, W B; Foschini, L; Fukazawa, Y; Funk, S; Fusco, P; Gargano, F; Gasparrini, D; Gehrels, N; Germani, S; Gibby, L; Giebels, B; Giglietto, N; Giordano, F; Glanzman, T; Godfrey, G; Granot, J; Greiner, J; Grenier, I A; Grondin, M-H; Grove, J E; Grupe, D; Guillemot, L; Guiriec, S; Hanabata, Y; Harding, A K; Hayashida, M; Hays, E; Hoversten, E A; Hughes, R E; Jóhannesson, G; Johnson, A S; Johnson, R P; Johnson, W N; Kamae, T; Katagiri, H; Kataoka, J; Kawai, N; Kerr, M; Kippen, R M; Knödlseder, J; Kocevski, D; Kouveliotou, C; Kuehn, F; Kuss, M; Lande, J; Latronico, L; Lemoine-Goumard, M; Longo, F; Loparco, F; Lott, B; Lovellette, M N; Lubrano, P; Madejski, G M; Makeev, A; Mazziotta, M N; McBreen, S; McEnery, J E; McGlynn, S; Mészáros, P; Meurer, C; Michelson, P F; Mitthumsiri, W; Mizuno, T; Moiseev, A A; Monte, C; Monzani, M E; Moretti, E; Morselli, A; Moskalenko, I V; Murgia, S; Nakamori, T; Nolan, P L; Norris, J P; Nuss, E; Ohno, M; Ohsugi, T; Omodei, N; Orlando, E; Ormes, J F; Ozaki, M; Paciesas, W S; Paneque, D; Panetta, J H; Parent, D; Pelassa, V; Pepe, M; Pesce-Rollins, M; Petrosian, V; Piron, F; Porter, T A; Preece, R; Rainò, S; Ramirez-Ruiz, E; Rando, R; Razzano, M; Razzaque, S; Reimer, A; Reimer, O; Reposeur, T; Ritz, S; Rochester, L S; Rodriguez, A Y; Roth, M; Ryde, F; Sadrozinski, H F-W; Sanchez, D; Sander, A; Saz Parkinson, P M; Scargle, J D; Schalk, T L; Sgrò, C; Siskind, E J; Smith, D A; Smith, P D; Spandre, G; Spinelli, P; Stamatikos, M; Stecker, F W; Strickman, M S; Suson, D J; Tajima, H; Takahashi, H; Takahashi, T; Tanaka, T; Thayer, J B; Thayer, J G; Thompson, D J; Tibaldo, L; Toma, K; Torres, D F; Tosti, G; Troja, E; Uchiyama, Y; Uehara, T; Usher, T L; van der Horst, A J; Vasileiou, V; Vilchez, N; Vitale, V; von Kienlin, A; Waite, A P; Wang, P; Wilson-Hodge, C; Winer, B L; Wood, K S; Wu, X F; Yamazaki, R; Ylinen, T; Ziegler, M
2009-11-19
A cornerstone of Einstein's special relativity is Lorentz invariance-the postulate that all observers measure exactly the same speed of light in vacuum, independent of photon-energy. While special relativity assumes that there is no fundamental length-scale associated with such invariance, there is a fundamental scale (the Planck scale, l(Planck) approximately 1.62 x 10(-33) cm or E(Planck) = M(Planck)c(2) approximately 1.22 x 10(19) GeV), at which quantum effects are expected to strongly affect the nature of space-time. There is great interest in the (not yet validated) idea that Lorentz invariance might break near the Planck scale. A key test of such violation of Lorentz invariance is a possible variation of photon speed with energy. Even a tiny variation in photon speed, when accumulated over cosmological light-travel times, may be revealed by observing sharp features in gamma-ray burst (GRB) light-curves. Here we report the detection of emission up to approximately 31 GeV from the distant and short GRB 090510. We find no evidence for the violation of Lorentz invariance, and place a lower limit of 1.2E(Planck) on the scale of a linear energy dependence (or an inverse wavelength dependence), subject to reasonable assumptions about the emission (equivalently we have an upper limit of l(Planck)/1.2 on the length scale of the effect). Our results disfavour quantum-gravity theories in which the quantum nature of space-time on a very small scale linearly alters the speed of light.
Limits to high-speed simulations of spiking neural networks using general-purpose computers
Friedemann eZenke
2014-09-01
Full Text Available To understand how the central nervous system performs computations using recurrent neuronal circuitry, simulations have become an indispensable tool for theoretical neuroscience. To study neuronal circuits and their ability to self-organize, increasing attention has been directed towards synaptic plasticity. In particular spike-timing-dependent plasticity (STDP creates specific demands for simulations of spiking neural networks. On the one hand a high temporal resolution is required to capture the millisecond timescale of typical STDP windows. On the other hand network simulations have to evolve over hours up to days, to capture the timescale of long-term plasticity. To do this efficiently, fast simulation speed is the crucial ingredient rather than large neuron numbers. Using different medium-sized network models consisting of several thousands of neurons and off-the-shelf hardware, we compare the simulation speed of the simulators: Brian, NEST and Neuron as well as our own simulator Auryn. Our results show that real-time simulations of different plastic network models are possible in parallel simulations in which numerical precision is not a primary concern. Even so, the speed-up margin of parallelism is limited and boosting simulation speeds beyond one tenth of real-time is difficult. By profiling simulation code we show that the run times of typical plastic network simulations encounter a hard boundary. This limit is partly due to latencies in the inter-process communications and thus cannot be overcome by increased parallelism. Overall these results show that to study plasticity in medium-sized spiking neural networks, adequate simulation tools are readily available which run efficiently on small clusters. However, to run simulations substantially faster than real-time, special hardware is a prerequisite.
Longitudinal Examination of Age-Predicted Symptom-Limited Exercise Maximum Heart Rate
Zhu, Na; Suarez, Jose; Sidney, Steve; Sternfeld, Barbara; Schreiner, Pamela J.; Carnethon, Mercedes R.; Lewis, Cora E.; Crow, Richard S.; Bouchard, Claude; Haskell, William; Jacobs, David R.
2010-01-01
Purpose To estimate the association of age with maximal heart rate (MHR). Methods Data were obtained in the Coronary Artery Risk Development in Young Adults (CARDIA) study. Participants were black and white men and women aged 18-30 in 1985-86 (year 0). A symptom-limited maximal graded exercise test was completed at years 0, 7, and 20 by 4969, 2583, and 2870 participants, respectively. After exclusion 9622 eligible tests remained. Results In all 9622 tests, estimated MHR (eMHR, beats/minute) had a quadratic relation to age in the age range 18 to 50 years, eMHR=179+0.29*age-0.011*age2. The age-MHR association was approximately linear in the restricted age ranges of consecutive tests. In 2215 people who completed both year 0 and 7 tests (age range 18 to 37), eMHR=189–0.35*age; and in 1574 people who completed both year 7 and 20 tests (age range 25 to 50), eMHR=199–0.63*age. In the lowest baseline BMI quartile, the rate of decline was 0.20 beats/minute/year between years 0-7 and 0.51 beats/minute/year between years 7-20; while in the highest baseline BMI quartile there was a linear rate of decline of approximately 0.7 beats/minute/year over the full age of 18 to 50 years. Conclusion Clinicians making exercise prescriptions should be aware that the loss of symptom-limited MHR is much slower at young adulthood and more pronounced in later adulthood. In particular, MHR loss is very slow in those with lowest BMI below age 40. PMID:20639723
2012-01-01
systems as well as vortex induced vibration systems . Section 3 presents a dynamic model of the hydrokinetic turbine system based on which a MPPT...turbines. In addition, hydrokinetic current energy can be converted into electrical energy by Vortex Induced Vibration (VIV) systems , in which a cylinder...Jiang, "Doubly- fed induction generator control for variable-speed wind power generation system ," in Proc. Mechatronics and Automation, 2009. ICMA 2009
Rebeca Bautista
2015-09-01
Full Text Available To prevent dangerous driving behaviors, the Spanish government has implemented public policies focused primarily on increasing the harshness of sanctions for violations of traffic laws. However, empirical evidence has demonstrated that other factors, such as social norms and one’s own value system, have an impact on people’s motivation to obey the law. A telephone survey was administered to a random sample of 570 Spanish drivers in order to determine the role played by each of these factors in compliance with two of the most flouted traffic rules. Logistic regression of the data allowed for the construction of models and arrive at the following conclusions: (1 social influence exerted by the reference group is a determining factor in compliance with both traffic laws; (2 legitimacy factors play an important role in complying with alcohol limits; and (3 variables from the deterrence approach only influenced compliance with speed limits, and then only moderately. The results of the present study suggest a need for a review of current public policy approaches for the prevention of dangerous driving behaviors.
Indranarain Ramlall
2012-06-01
Full Text Available Many countries have adopted important policies in view of curbing the number of injuries/fatal road accidents with the most important being speed limit enforcement. In that respect, Mauritius has recently embarked on a strategy of using cameras in view of detecting violations to speed limits. However, the empirical literature on speed limit offenders is still very poor in terms of modeling. In essence, this paper constitutes the very first study that provides sound econometric modeling for speed limit offenders. Findings suggest that vanilla GARCH can be used to model the number of speed limit offenders. Above all, leverage effects are also noted, clearly showing the importance of the type of traffic flow of speed limit offenders which underpins the non-compliance/breach to speed limits. Furthermore, results show the presence of strong weekend effects as confirmed by the dummy variable. The research is expected to provide a momentum in the use of GARCH models for traffic modeling not only for Mauritius but also for other countries in the world.
Vlase, A.; Blăjină, O.; Iacob, M.; Darie, V.
2015-11-01
Two addressed issues in the research regarding the cutting machinability, establishing of the optimum cutting processing conditions and the optimum cutting regime, do not yet have sufficient data for solving. For this reason, in the paper it is proposed the optimization of the tool life and the cutting speed at the drilling of a certain stainless steel in terms of the maximum productivity. For this purpose, a nonlinear programming mathematical model to maximize the productivity at the drilling of the steel is developed in the paper. The optimum cutting tool life and the associated cutting tool speed are obtained by solving the numerical mathematical model. Using this proposed model allows increasing the accuracy in the prediction of the productivity for the drilling of a certain stainless steel and getting the optimum tool life and the optimum cutting speed for the maximum productivity. The results presented in this paper can be used in the production activity, in order to increase the productivity of the stainless steels machining. Also new research directions for the specialists in this interested field may come off from this paper.
Özgüç, A.; Kilcik, A.; Georgieva, K.; Kirov, B.
2016-05-01
On the basis of a morphological analysis of yearly values of the maximum coronal mass ejection (CME) speed index, the sunspot number and total sunspot area, sunspot magnetic field, and solar flare index, the solar wind speed and interplanetary magnetic field strength, and the geomagnetic Ap and D_{st} indices, we point out the particularities of solar and geomagnetic activity during the last Cycle 23, the long minimum that followed it, and the ascending branch of Cycle 24. We also analyze the temporal offset between the maximum CME speed index and the above-mentioned solar, geomagnetic, and interplanetary indices. It is found that this solar activity index, analyzed jointly with other solar activity, interplanetary parameters, and geomagnetic activity indices, shows a hysteresis phenomenon. It is observed that these parameters follow different paths for the ascending and descending phases of Cycle 23. The hysteresis phenomenon represents a clue in the search for physical processes responsible for linking the solar activity to near-Earth and geomagnetic responses.
Oxygen delivery does not limit peak running speed during incremental downhill running to exhaustion.
Liefeldt, G; Noakes, T D; Dennis, S C
1992-01-01
Oxygen consumption (VO2), ventilation (VI), respiratory exchange ratio (R), stride frequency and blood lactate concentrations were measured continuously in nine trained athletes during two continuous incremental treadmill runs to exhaustion on gradients of either 0 degree or -3 degrees. Compared to the run at 0 degree gradient, the athletes reached significantly higher maximal treadmill velocities but significantly lower VO2, VI, R and peak blood lactate concentrations (P less than 0.001) during downhill running. These lower VO2 and blood lactate concentrations at exhaustion indicated that factors other than oxygen delivery limited maximal performance during the downhill run. In contrast, stride frequencies were similar at each treadmill velocity; the higher maximal speed during the downhill run was achieved with a significantly longer stride length (P less than 0.001); maximal stride frequency was the same between tests. Equivalent maximal stride frequencies suggested that factors determining the rate of lower limb stride recovery may have limited maximal running speed during downhill running and, possibly, also during horizontal running.
Andrei BIRMAN
2011-12-01
Full Text Available This study briefly presents theoretical aspects related to the relationship between inflation and economic growth and provides an empirical study for the Romanian economy, for the period 2000 – 2011. The econometric methodology used is that of vector auto-regressions.The results showed that a sudden increase in the change of the output gap (i.e. a shock to the growth rate of the output gap does not determine an increase in CPI. Hence, the hypothesis of the existence of a speed limit effect in Romania is rejected. In concrete terms, this means that the monetary authorities should not fear for eventual inflationary pressures when sudden increases of demand arise, if the output gap is negative (the potential output is higher that the effective output. The National Bank of Romania may avoid, therefore, taking some monetary policy decisions meant to temper the rise in inflation (as would have been the case if a speed limit effect was present but which would have induced unnecessary volatility into the output. However, the study indicates that National Bank of Romania should communicate to the public the state of the economy in order to timely anchor the inflation expectations. This is a very important aspect, since the inflation expectations firmly react to a shock into the growth rate of the output gap, i.e. to a strong increase in the effective output.The study also showed a positive response of the growth rate of the output gap to a positive shock in inflation, with a maximum effect after three quarters. This shows that the inflation was mainly driven by demand factors in the analysed period, with the consumers increasing current consumption in order to avoid the future higher prices and with the economic agents increasing the supply such as to maximise the unitary profits. Also, this result shows a rather inelastic demand or a possible captivity of consumers in the face of producers.
Quantum speed limits of a qubit system interacting with a nonequilibrium environment
He, Zhi; Yao, Chun-Mei; Li, Li; Wang, Qiong
2016-08-01
The speed of evolution of a qubit undergoing a nonequilibrium environment with spectral density of general ohmic form is investigated. First we reveal non-Markovianity of the model, and find that the non-Markovianity quantified by information backflow of Breuer et al. [Phys. Rev. Lett. 103 210401 (2009)] displays a nonmonotonic behavior for different values of the ohmicity parameter s in fixed other parameters and the maximal non-Markovianity can be achieved at a specified value s. We also find that the non-Markovianity displays a nonmonotonic behavior with the change of a phase control parameter. Then we further discuss the relationship between quantum speed limit (QSL) time and non-Markovianity of the open-qubit system for any initial states including pure and mixed states. By investigation, we find that the QSL time of a qubit with any initial states can be expressed by a simple factorization law: the QSL time of a qubit with any qubit-initial states are equal to the product of the coherence of the initial state and the QSL time of maximally coherent states, where the QSL time of the maximally coherent states are jointly determined by the non-Markovianity, decoherence factor and a given driving time. Moreover, we also find that the speed of quantum evolution can be obviously accelerated in the wide range of the ohmicity parameter, i.e., from sub-Ohmic to Ohmic and super-Ohmic cases, which is different from the thermal equilibrium environment case. Project supported by the National Natural Science Foundation of China (Grants Nos. 61505053 and 61475045), the Natural Science Foundation of Hunan Province, China(Grant No. 2015JJ3092), the School Foundation from the Hunan University of Arts and Science (Grant No. 14ZD01), the Fund from the Key Laboratory of Photoelectric Information Integration and Optical Manufacturing Technology of Hunan Province, China, and the Construction Program of the Key Discipline in Hunan University of Arts and Science (Optics).
Marshall, Andrew R J; Ker, Pin Jern; Krysa, Andrey; David, John P R; Tan, Chee Hing
2011-11-07
High bandwidth, uncooled, Indium Arsenide (InAs) electron avalanche photodiodes (e-APDs) with unique and highly desirable characteristics are reported. The e-APDs exhibit a 3dB bandwidth of 3.5 GHz which, unlike that of conventional APDs, is shown not to reduce with increasing avalanche gain. Hence these InAs e-APDs demonstrate a characteristic of theoretically ideal electron only APDs, the absence of a gain-bandwidth product limit. This is important because gain-bandwidth products restrict the maximum exploitable gain in all conventional high bandwidth APDs. Non-limiting gain-bandwidth products up to 580 GHz have been measured on these first high bandwidth e-APDs.
Beberniss, Timothy J.; Ehrhardt, David A.
2017-03-01
A review of the extensive studies on the feasibility and practicality of utilizing high-speed 3 dimensional digital image correlation (3D-DIC) for various random vibration measurement applications is presented. Demonstrated capabilities include finite element model updating utilizing full-field 3D-DIC static displacements, modal survey natural frequencies, damping, and mode shape results from 3D-DIC are baselined against laser Doppler vibrometry (LDV), a comparison between foil strain gage and 3D-DIC strain, and finally the unique application to a high-speed wind tunnel fluid-structure interaction study. Results show good agreement between 3D-DIC and more traditional vibration measurement techniques. Unfortunately, 3D-DIC vibration measurement is not without its limitations, which are also identified and explored in this study. The out-of-plane sensitivity required for vibration measurement for 3D-DIC is orders of magnitude less than LDV making higher frequency displacements difficult to sense. Furthermore, the digital cameras used to capture the DIC images have no filter to eliminate temporal aliasing of the digitized signal. Ultimately DIC is demonstrated as a valid alternative means to measure structural vibrations while one unique application achieves success where more traditional methods would fail.
Relationship between quantum speed limit time and memory time in a photonic-band-gap environment
Wang, J.; Wu, Y. N.; Mo, M. L.; Zhang, H. Z.
2016-12-01
Non-Markovian effect is found to be able to decrease the quantum speed limit (QSL) time, and hence to enhance the intrinsic speed of quantum evolution. Although a reservoir with larger degree of non-Markovianity may seem like it should cause smaller QSL times, this seemingly intuitive thinking may not always be true. We illustrate this by investigating the QSL time of a qubit that is coupled to a two-band photonic-band-gap (PBG) environment. We show how the QSL time is influenced by the coherent property of the reservoir and the band-gap width. In particular, we find that the decrease of the QSL time is not attributed to the increasing non-Markovianity, while the memory time of the environment can be seen as an essential reflection to the QSL time. So, the QSL time provides a further insight and sharper identification of memory time in a PBG environment. We also discuss a feasible experimental realization of our prediction.
Fundamental High-Speed Limits in Single-Molecule, Single-Cell, and Nanoscale Force Spectroscopies
2016-01-01
Force spectroscopy is enhancing our understanding of single-biomolecule, single-cell, and nanoscale mechanics. Force spectroscopy postulates the proportionality between the interaction force and the instantaneous probe deflection. By studying the probe dynamics, we demonstrate that the total force acting on the probe has three different components: the interaction, the hydrodynamic, and the inertial. The amplitudes of those components depend on the ratio between the resonant frequency and the frequency at which the data are measured. A force–distance curve provides a faithful measurement of the interaction force between two molecules when the inertial and hydrodynamic components are negligible. Otherwise, force spectroscopy measurements will underestimate the value of unbinding forces. Neglecting the above force components requires the use of frequency ratios in the 50–500 range. These ratios will limit the use of high-speed methods in force spectroscopy. The theory is supported by numerical simulations. PMID:27359243
Drivers' compliance with speed limits: an application of the theory of planned behavior.
Elliott, Mark A; Armitage, Christopher J; Baughan, Christopher J
2003-10-01
The theory of planned behavior (TPB; I. Ajzen, 1985) was applied to drivers' compliance with speed limits. Questionnaire data were collected for 598 drivers at 2 time points separated by 3 months. TPB variables, demographic information, and self-reported prior behavior were measured at Time 1, and self-reported subsequent behavior was measured at Time 2. In line with the TPB, attitude, subjective norm, and perceived control were positively associated with behavioral intention, and intention and perceived control were positively associated with subsequent behavior. TPB variables mediated the effects of age and gender on behavior. Prior behavior was found to moderate the perceived control-intention and perceived control-subsequent behavior relationships. Practical implications of the findings for road safety and possible avenues for further research are discussed.
Effects of vehicle-pedestrian interaction and speed limit on traffic performance of intersections
Li, Xiang; Sun, Jian-Qiao
2016-10-01
The intersection model consisting of vehicle model, pedestrian model, pedestrian-vehicle interaction model and intersection rules has been presented in this paper. The well-established vehicle and pedestrian movement models in the literature are combined and applied to the intersection system with additional rules. Extensive numerical simulations with different scenarios are carried out. The effects of road speed limit, vehicle arrival rate, pedestrian regularity rate and vehicle rational rate on the intersection performance are quantitatively investigated. Three measures of the traffic performance are studied including transportation efficiency, energy economy and traffic safety. We have found that the energy economy can be achieved with the high transportation efficiency, and that the traffic safety is in conflict with the efficiency. Furthermore, we have found that the pedestrian interference makes the intersection performance worse, resulting in lower transportation efficiency, more energy consumptions and higher safety risk.
Kinoshita, Takashi, E-mail: tkino@med.kurume-u.ac.jp [Division of Respirology, Neurology, and Rheumatology, Department of Medicine, Kurume University School of Medicine, Kurume (Japan); Kawayama, Tomotaka, E-mail: kawayama_tomotaka@med.kurume-u.ac.jp [Division of Respirology, Neurology, and Rheumatology, Department of Medicine, Kurume University School of Medicine, Kurume (Japan); Imamura, Youhei, E-mail: mamura_youhei@med.kurume-u.ac.jp [Division of Respirology, Neurology, and Rheumatology, Department of Medicine, Kurume University School of Medicine, Kurume (Japan); Sakazaki, Yuki, E-mail: sakazaki@med.kurume-u.ac.jp [Division of Respirology, Neurology, and Rheumatology, Department of Medicine, Kurume University School of Medicine, Kurume (Japan); Hirai, Ryo, E-mail: hirai_ryou@kurume-u.ac.jp [Division of Respirology, Neurology, and Rheumatology, Department of Medicine, Kurume University School of Medicine, Kurume (Japan); Ishii, Hidenobu, E-mail: shii_hidenobu@med.kurume-u.ac.jp [Division of Respirology, Neurology, and Rheumatology, Department of Medicine, Kurume University School of Medicine, Kurume (Japan); Suetomo, Masashi, E-mail: jin_t_f_c@yahoo.co.jp [Division of Respirology, Neurology, and Rheumatology, Department of Medicine, Kurume University School of Medicine, Kurume (Japan); Matsunaga, Kazuko, E-mail: kmatsunaga@kouhoukai.or.jp [Division of Respirology, Neurology, and Rheumatology, Department of Medicine, Kurume University School of Medicine, Kurume (Japan); Azuma, Koichi, E-mail: azuma@med.kurume-u.ac.jp [Division of Respirology, Neurology, and Rheumatology, Department of Medicine, Kurume University School of Medicine, Kurume (Japan); Fujimoto, Kiminori, E-mail: kimichan@med.kurume-u.ac.jp [Department of Radiology, Kurume University School of Medicine, Kurume (Japan); Hoshino, Tomoaki, E-mail: hoshino@med.kurume-u.ac.jp [Division of Respirology, Neurology, and Rheumatology, Department of Medicine, Kurume University School of Medicine, Kurume (Japan)
2015-04-15
Highlights: •It is often to use computed tomography (CT) scan for diagnosis of chronic obstructive pulmonary disease. •CT scan is more expensive and higher. •A plane chest radiography more simple and cheap. Moreover, it is useful as detection of pulmonary emphysema, but not airflow limitation. •Our study demonstrated that the maximum inspiratory and expiratory plane chest radiography technique could detect severe airflow limitations. •We believe that the technique is helpful to diagnose the patients with chronic obstructive pulmonary disease. -- Abstract: Background: The usefulness of paired maximum inspiratory and expiratory (I/E) plain chest radiography (pCR) for diagnosis of chronic obstructive pulmonary disease (COPD) is still unclear. Objectives: We examined whether measurement of the I/E ratio using paired I/E pCR could be used for detection of airflow limitation in patients with COPD. Methods: Eighty patients with COPD (GOLD stage I = 23, stage II = 32, stage III = 15, stage IV = 10) and 34 control subjects were enrolled. The I/E ratios of frontal and lateral lung areas, and lung distance between the apex and base on pCR views were analyzed quantitatively. Pulmonary function parameters were measured at the same time. Results: The I/E ratios for the frontal lung area (1.25 ± 0.01), the lateral lung area (1.29 ± 0.01), and the lung distance (1.18 ± 0.01) were significantly (p < 0.05) reduced in COPD patients compared with controls (1.31 ± 0.02 and 1.38 ± 0.02, and 1.22 ± 0.01, respectively). The I/E ratios in frontal and lateral areas, and lung distance were significantly (p < 0.05) reduced in severe (GOLD stage III) and very severe (GOLD stage IV) COPD as compared to control subjects, although the I/E ratios did not differ significantly between severe and very severe COPD. Moreover, the I/E ratios were significantly correlated with pulmonary function parameters. Conclusions: Measurement of I/E ratios on paired I/E pCR is simple and
A Brief Analysis of the Action Speed of the Elevator Speed Limiter%浅析电梯用限速器的动作速度要求
袁晓金; 段志梅; 周莎
2015-01-01
根据《电梯制造与安装安全规范（GB7588-2003）》中对限速器动作速度的要求，通过数学公式描述的方式，详细分析了在限速器－安全钳系统（轿厢下行超速保护装置）中以及轿厢上行超速保护装置中的限速器动作速度要求。数学公式的描述简单明了、通俗易懂。%According to the requirement of speed limiter action speed in GB7588-2003, The article detailed analyzed the action speed of the speed limiter in the car downward overspeed protection device and car upgoing overspeed protection device by the way of mathematical formula. The merits of the mathematical formulas are simple and clear, popular and easy to understand.
El-Basyouny, Karim; El-Bassiouni, Mohamed Yahia
2013-03-01
To address the speeding problem in residential areas, the City of Edmonton initiated a pilot project to reduce the posted speed limit from 50km/h to 40km/h within six residential communities. This paper investigates the community perceptions of traffic safety within the six pilot communities in two phases: prior to project initiation (pre-pilot) and following the end of the project (post-pilot). This objective was accomplished by analyzing the results of two random dialing telephone surveys comprising 300 residents each. A preliminary analysis showed compatible demographic configurations for the two samples and confirmed that the residents were aware of both the posted speed limits and the adopted speed management controls. For the confirmatory factor analysis (CFA), a two-group (pre-pilot and post-pilot) three-factor model was used to assess the residents' perceptions of the speeding behavior (Speeding), their concerns about traffic safety issues (Concerns), and their perceptions of traffic safety (Safety). Comparing the CFA results of the post-pilot survey versus those of the pre-pilot survey, it was evident that there was a significant decrease in Speeding and Concerns accompanied by a significant increase in Safety. A structural equations model (SEM) was also fitted to the data in order to assess the impact of Speeding and Concerns on Safety. The results showed that Concerns increase significantly with Speeding, and that both factors have significant negative impacts on Safety. However, while the impact of Concerns on Safety was direct, that of Speeding on Safety was largely indirect (i.e., mediated through Concerns). Overall, the multivariate analysis has demonstrated that the pilot project was successful in improving the residents' perceptions of traffic safety in their community.
Effects of heterogeneous traffic with speed limit zone on the car accidents
Marzoug, R.; Lakouari, N.; Bentaleb, K.; Ez-Zahraouy, H.; Benyoussef, A.
2016-06-01
Using the extended Nagel-Schreckenberg (NS) model, we numerically study the impact of the heterogeneity of traffic with speed limit zone (SLZ) on the probability of occurrence of car accidents (Pac). SLZ in the heterogeneous traffic has an important effect, typically in the mixture velocities case. In the deterministic case, SLZ leads to the appearance of car accidents even in the low densities, in this region Pac increases with increasing of fraction of fast vehicles (Ff). In the nondeterministic case, SLZ decreases the effect of braking probability Pb in the low densities. Furthermore, the impact of multi-SLZ on the probability Pac is also studied. In contrast with the homogeneous case [X. Li, H. Kuang, Y. Fan and G. Zhang, Int. J. Mod. Phys. C 25 (2014) 1450036], it is found that in the low densities the probability Pac without SLZ (n = 0) is low than Pac with multi-SLZ (n > 0). However, the existence of multi-SLZ in the road decreases the risk of collision in the congestion phase.
Speed limit in internal space of domain walls via all-order effective action of moduli motion
Eto, Minoru; Hashimoto, Koji
2016-03-01
We find that motion in internal moduli spaces of generic domain walls has an upper bound for its velocity. Our finding is based on our generic formula for all-order effective actions of internal moduli parameter of domain wall solitons. It is known that the Nambu-Goldstone mode Z associated with spontaneous breaking of translation symmetry obeys a Nambu-Goto effective Lagrangian √{1 -(∂0Z )2 } detecting the speed of light (|∂0Z |=1 ) in the target spacetime. Solitons can have internal moduli parameters as well, associated with a breaking of internal symmetries such as a phase rotation acting on a field. We obtain, for generic domain walls, an effective Lagrangian of the internal moduli ɛ to all orders in (∂ɛ ). The Lagrangian is given by a function of the Nambu-Goto Lagrangian: L =g (√{1 +(∂μɛ )2 }). This shows generically the existence of an upper bound on ∂0ɛ , i.e., a speed limit in the internal space. The speed limit exists even for solitons in some nonrelativistic field theories, where we find that ɛ is a type I Nambu-Goldstone mode that also obeys a nonlinear dispersion to reach the speed limit. This offers a possibility of detecting the speed limit in condensed matter experiments.
14 CFR 23.1507 - Operating maneuvering speed.
2010-01-01
... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Operating maneuvering speed. 23.1507... Limitations and Information § 23.1507 Operating maneuvering speed. The maximum operating maneuvering speed, VO, must be established as an operating limitation. VO is a selected speed that is not greater than...
Janská, Veronika; Jiménez-Alfaro, Borja; Chytrý, Milan; Divíšek, Jan; Anenkhonov, Oleg; Korolyuk, Andrey; Lashchinskyi, Nikolai; Culek, Martin
2017-03-01
We modelled the European distribution of vegetation types at the Last Glacial Maximum (LGM) using present-day data from Siberia, a region hypothesized to be a modern analogue of European glacial climate. Distribution models were calibrated with current climate using 6274 vegetation-plot records surveyed in Siberia. Out of 22 initially used vegetation types, good or moderately good models in terms of statistical validation and expert-based evaluation were computed for 18 types, which were then projected to European climate at the LGM. The resulting distributions were generally consistent with reconstructions based on pollen records and dynamic vegetation models. Spatial predictions were most reliable for steppe, forest-steppe, taiga, tundra, fens and bogs in eastern and central Europe, which had LGM climate more similar to present-day Siberia. The models for western and southern Europe, regions with a lower degree of climatic analogy, were only reliable for mires and steppe vegetation, respectively. Modelling LGM vegetation types for the wetter and warmer regions of Europe would therefore require gathering calibration data from outside Siberia. Our approach adds value to the reconstruction of vegetation at the LGM, which is limited by scarcity of pollen and macrofossil data, suggesting where specific habitats could have occurred. Despite the uncertainties of climatic extrapolations and the difficulty of validating the projections for vegetation types, the integration of palaeodistribution modelling with other approaches has a great potential for improving our understanding of biodiversity patterns during the LGM.
Beltrán, M C; Romero, T; Althaus, R L; Molina, M P
2013-01-01
The Charm maximum residue limit β-lactam and tetracycline test (Charm MRL BLTET; Charm Sciences Inc., Lawrence, MA) is an immunoreceptor assay utilizing Rapid One-Step Assay lateral flow technology that detects...
Nwosu, Cajethan M.; Ogbuka, Cosmas U.; Oti, Stephen E.
2017-08-01
This paper presents a control model design capable of inhibiting the phenomenal rise in the DC-link voltage during grid- fault condition in a variable speed wind turbine. Against the use of power circuit protection strategies with inherent limitations in fault ride-through capability, a control circuit algorithm capable of limiting the DC-link voltage rise which in turn bears dynamics that has direct influence on the characteristics of the rotor voltage especially during grid faults is here proposed. The model results so obtained compare favorably with the simulation results as obtained in a MATLAB/SIMULINK environment. The generated model may therefore be used to predict near accurately the nature of DC-link voltage variations during fault given some factors which include speed and speed mode of operation, the value of damping resistor relative to half the product of inner loop current control bandwidth and the filter inductance.
Hegyi, A.; Netten, B.D.; Wang, M.; Schakel, W.; Schreiter, T.; Yuan, Y.; Arem, B. van; Alkim, T.
2013-01-01
The SPECIALIST algorithm can resolve jam waves on freeways using roadside technology: detector loops and speed limit gantries. In this paper we extend the algorithm, enabling the integration with cooperative system technologies and other road side detectors, such as in-car detection and actuation, a
Castro-Santos, Theodore; Sanz-Ronda, Francisco Javier; Ruiz-Legazpi, Jorge
2013-01-01
Sprinting behavior of free-ranging fish has long been thought to exceed that of captive fish. Here we present data from wild-caught brook trout (Salvelinus fontinalis) and brown trout (Salmo trutta), volitionally entering and sprinting against high-velocity flows in an open-channel flume. Performance of the two species was nearly identical, with the species attaining absolute speeds > 25 body lengths·s−1. These speeds far exceed previously published observations for any salmonid species and contribute to the mounting evidence that commonly accepted estimates of swimming performance are low. Brook trout demonstrated two distinct modes in the relationship between swim speed and fatigue time, similar to the shift from prolonged to sprint mode described by other authors, but in this case occurring at speeds > 19 body lengths·s−1. This is the first demonstration of multiple modes of sprint swimming at such high swim speeds. Neither species optimized for distance maximization, however, indicating that physiological limits alone are poor predictors of swimming performance. By combining distributions of volitional swim speeds with endurance, we were able to account for >80% of the variation in distance traversed by both species.
Mikosch, Thomas Valentin; Moser, Martin
2013-01-01
We investigate the maximum increment of a random walk with heavy-tailed jump size distribution. Here heavy-tailedness is understood as regular variation of the finite-dimensional distributions. The jump sizes constitute a strictly stationary sequence. Using a continuous mapping argument acting on...... on the point processes of the normalized jump sizes, we prove that the maximum increment of the random walk converges in distribution to a Fréchet distributed random variable....
Limits, modeling and design of high-speed permanent magnet machines
Borisavljevic, A.
2011-01-01
There is a growing number of applications that require fast-rotating machines; motivation for this thesis comes from a project in which downsized spindles for micro-machining have been researched (TU Delft Microfactory project). The thesis focuses on analysis and design of high-speed PM machines and
A limit on the variation of the speed of light arising from quantum gravity effects
Abdo, A. A.; Ackermann, M.; Ajello, M.; Asano, K.; Atwood, W. B.; Axelsson, M.; Baldini, L.; Ballet, J.; Barbiellini, G.; Baring, M. G.; Bastieri, D.; Bechtol, K.; Bellazzini, R.; Berenji, B.; Bhat, P. N.; Bissaldi, E.; Bloom, E. D.; Bonamente, E.; Bonnell, J.; Borgland, A. W.; Bouvier, A.; Bregeon, J.; Brez, A.; Briggs, M. S.; Brigida, M.; Bruel, P.; Burgess, J. M.; Burnett, T. H.; Caliandro, G. A.; Cameron, R. A.; Caraveo, P. A.; Casandjian, J. M.; Cecchi, C.; Celik, Oe; Chaplin, V.; Charles, E.; Cheung, C. C.; Chiang, J.; Ciprini, S.; Claus, R.; Cohen-Tanugi, J.; Cominsky, L. R.; Connaughton, V.; Conrad, J.; Cutini, S.; Dermer, C. D.; de Angelis, A.; de Palma, F.; Digel, S. W.; Dingus, B. L.; do Couto e Silva, E.; Drell, P. S.; Dubois, R.; Dumora, D.; Farnier, C.; Favuzzi, C.; Fegan, S. J.; Finke, J.; Fishman, G.; Focke, W. B.; Foschini, L.; Fukazawa, Y.; Funk, S.; Fusco, P.; Gargano, F.; Gasparrini, D.; Gehrels, N.; Germani, S.; Gibby, L.; Giebels, B.; Giglietto, N.; Giordano, F.; Glanzman, T.; Godfrey, G.; Granot, J.; Greiner, J.; Grenier, I. A.; Grondin, M. -H.; Grove, J. E.; Grupe, D.; Guillemot, L.; Guiriec, S.; Hanabata, Y.; Harding, A. K.; Hayashida, M.; Hays, E.; Hoversten, E. A.; Hughes, R. E.; Johannesson, G.; Johnson, A. S.; Johnson, R. P.; Johnson, W. N.; Kamae, T.; Katagiri, H.; Kataoka, J.; Kawai, N.; Kerr, M.; Kippen, R. M.; Knoedlseder, J.; Kocevski, D.; Kouveliotou, C.; Kuehn, F.; Kuss, M.; Lande, J.; Latronico, L.; Lemoine-Goumard, M.; Longo, F.; Loparco, F.; Lott, B.; Lovellette, M. N.; Lubrano, P.; Madejski, G. M.; Makeev, A.; Mazziotta, M. N.; McBreen, S.; McEnery, J. E.; McGlynn, S.; Meszaros, P.; Meurer, C.; Michelson, P. F.; Mitthumsiri, W.; Mizuno, T.; Moiseev, A. A.; Monte, C.; Monzani, M. E.; Moretti, E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Nakamori, T.; Nolan, P. L.; Norris, J. P.; Nuss, E.; Ohno, M.; Ohsugi, T.; Omodei, N.; Orlando, E.; Ormes, J. F.; Ozaki, M.; Paciesas, W. S.; Paneque, D.; Panetta, J. H.; Parent, D.; Pelassa, V.; Pepe, M.; Pesce-Rollins, M.; Petrosian, V.; Piron, F.; Porter, T. A.; Preece, R.; Raino, S.; Ramirez-Ruiz, E.; Rando, R.; Razzano, M.; Razzaque, S.; Reimer, A.; Reimer, O.; Reposeur, T.; Ritz, S.; Rochester, L. S.; Rodriguez, A. Y.; Roth, M.; Ryde, F.; Sadrozinski, H. F. -W.; Sanchez, D.; Sander, A.; Parkinson, P. M. Saz; Scargle, J. D.; Schalk, T. L.; Sgro, C.; Siskind, E. J.; Smith, D. A.; Smith, P. D.; Spandre, G.; Spinelli, P.; Stamatikos, M.; Stecker, F. W.; Strickman, M. S.; Suson, D. J.; Tajima, H.; Takahashi, H.; Takahashi, T.; Tanaka, T.; Thayer, J. B.; Thayer, J. G.; Thompson, D. J.; Tibaldo, L.; Toma, K.; Torres, D. F.; Tosti, G.; Troja, E.; Uchiyama, Y.; Uehara, T.; Usher, T. L.; van der Horst, A. J.; Vasileiou, V.; Vilchez, N.; Vitale, V.; von Kienlin, A.; Waite, A. P.; Wang, P.; Wilson-Hodge, C.; Winer, B. L.; Wood, K. S.; Wu, X. F.; Yamazaki, R.; Ylinen, T.; Ziegler, M.
2009-01-01
A cornerstone of Einstein's special relativity is Lorentz invariance-the postulate that all observers measure exactly the same speed of light in vacuum, independent of photon-energy. While special relativity assumes that there is no fundamental length-scale associated with such invariance, there is
高速公路主线收费站可变限速控制%Variable speed-limit control before expressway mainline toll station
蒲云; 胡路; 蒋阳升; 朱娟秀; 彭博
2012-01-01
以事故率最小为目标，以费用与速度限制为约束条件，建立可变限速控制优化模型，确定可变信息板数目与相应的可变限速值。采用交通波理论模型计算可变信息板设置间距，并利用Vissim仿真软件对模型进行验证。利用不同交通流量下的单向双车道6个收费窗口的高速公路，进一步模拟可变限速控制与静态限速控制。试验结果表明：在高速公路主线收费站排队广场前应设4块可变信息板，设置间距分别为1293、2695、4056m，仿真结果与交通波理论模型计算值的相对误差最小为3．9％，最大为9．5％；可变限速控制中，通过车辆数较静态限速控制增长51．82％，行程时间与排队长度分别平均缩短15．81％、18．98％，验证了本文设计体系的合理性。%An optimization model of variable speed-limit control with the object of the least accident rate and the limitations of cost and speed was set up, in which the number of variable message signs and corresponding variable limit speeds were determined. The distances between variable message signs were computed by using the traffic wave model, and the optimization model was verified by using the simulation software Vissim. For different traffic flows, variable speed-limit control and static speed-limit control were simulated on the expressway with two- lanes and six toll windows in single direction. Analysis result shows that when 4 variable message signs with setting separation distances of 1 293, 2 695 and 4 056 m apart are installed before the queuing square of expressway mainline toll station, the minimum relative error between simulation result and calculated values of traffic wave model is 3.9~, and the maximum is 9.5%. Compared with static speed-limit control, passing vehicle number in variable speed-limit control rises by 51.82%, average travel time and queue length decrease by 15.81%and 18.98% respectively, which proves that the
The limits of modifying migration speed to adjust to climate change
Schmaljohann, Heiko; Both, Christiaan
2017-08-01
Predicting the range of variation over which organisms can adjust to environmental change is a major challenge in ecology. This is exemplified in migratory birds which experience changes in different habitats throughout the annual cycle. Earlier studies showed European population trends declining strongest in migrant species with least adjustment in spring arrival time. Thus, the increasing mismatches with other trophic levels in seasonal breeding areas probably contribute to their large-scale decline. Here we quantify the potential range of adjusting spring arrival dates through modifying migration speeds by reviewing 49 tracking studies. Among-individual variation in migration speed was mainly determined by the relatively short stop-over duration. Assuming this population response reflects individual phenotypic plasticity, we calculated the potential for phenotypic plasticity to speed-up migration by reducing stop-over duration. Even a 50% reduction would lead to a mere two-day advance in arrival, considering adjustments on the final 2,000 km of the spring journey. Hence, in contrast to previous studies, flexibility in the major determinant of migration duration seems insufficient to adjust to ongoing climate change, and is unlikely to explain some of the observed arrival advancements in long-distance migrants.
Wegman, F.C.M.
1981-01-01
This paper is a contribution to the international OECD symposium "the effect of speed limits on traffic accidents and transport energy use", held in Dublin on 6-8 October 1981. Outlined are the problems of actual speeds, how speed is influenced, speed restrictions etc. in the Netherlands. In additio
Verghese, Joe; Wang, Cuiling; Holtzer, Roee
2011-05-01
To examine the ability of clinic-based assessments of gait speed to capture limitations in a broad range of home- and community-based activities. Cross-sectional study. Community-based aging cohort study. Community-residing subjects (N=655; 61% women; age ≥70y; mean, 80.4y). None. Limitations on 3 gait-related activities of daily living (walking inside home, climbing up and down stairs) and 6 motor-based but gait-independent activities (bathing, dressing, getting up from a chair, toileting, shopping, using public transportation). Gait speed was associated with the presence of self-reported difficulty for all 3 home-based activities that were directly gait related and 5 of 6 motor-based activities. Gait speed of 1m/s or less was associated with increased risk for limitations on at least 1 of the 9 selected activities (odds ratio, 3.21; 95% confidence interval, 2.24-4.58; Pspeed measured in clinical settings has ecologic validity as a clinical marker of functional status in older adults for use in clinical and research settings. Copyright © 2011 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.
A low upper limit on the subsurface rise speed of solar active regions
Birch, Aaron C; Braun, Douglas C; Cameron, Robert; Gizon, Laurent; Löptien, Björn; Rempel, Matthias
2016-01-01
Magnetic field emerges at the surface of the Sun as sunspots and active regions. This process generates a poloidal magnetic field from a rising toroidal flux tube, it is a crucial but poorly understood aspect of the solar dynamo. The emergence of magnetic field is also important because it is a key driver of solar activity. We show that measurements of horizontal flows at the solar surface around emerging active regions, in combination with numerical simulations of solar magnetoconvection, can constrain the subsurface rise speed of emerging magnetic flux. The observed flows imply that the rise speed of the magnetic field is no larger than 150 m/s at a depth of 20 Mm, that is, well below the prediction of the (standard) thin flux tube model but in the range expected for convective velocities at this depth. We conclude that convective flows control the dynamics of rising flux tubes in the upper layers of the Sun and cannot be neglected in models of flux emergence.
Speed limit in internal space of domain walls via all-order effective action of moduli motion
Eto, Minoru
2015-01-01
We find that motion in internal moduli spaces of generic domain walls has an upper bound for its velocity. Our finding is based on our generic formula for all-order effective actions of internal moduli parameter of domain wall solitons. It is known that the Nambu-Goldstone mode $Z$ associated with spontaneous breaking of translation symmetry obeys a Nambu-Goto effective Lagrangian $\\sqrt{1 - (\\partial_0 Z)^2}$ detecting the speed of light ($|\\partial_0 Z|=1$) in the target spacetime. Solitons can have internal moduli parameters as well, associated with a breaking of internal symmetries such as a phase rotation acting on a field. We obtain, for generic domain walls, an effective Lagrangian of the internal moduli $\\epsilon$ to all order in $(\\partial \\epsilon)$. The Lagrangian is given by a function of the Nambu-Goto Lagrangian: $L = g(\\sqrt{1 + (\\partial_\\mu \\epsilon)^2})$. This shows generically the existence of an upper bound on $\\partial_0 \\epsilon$, i.e. a speed limit in the internal space. The speed limit...
Primativo, Silvia; Spinelli, Donatella; Zoccolotti, Pierluigi; De Luca, Maria; Martelli, Marialuisa
2016-01-01
Adults read at high speed, but estimates of their reading rate vary greatly, i.e., from 100 to 1500 words per minute (wpm). This discrepancy is likely due to different recording methods and to the different perceptual and cognitive processes involved in specific test conditions. The present study investigated the origins of these notable differences in RSVP reading rate (RR). In six experiments we investigated the role of many different perceptual and cognitive variables. The presence of a mask caused a steep decline in reading rate, with an estimated masking cost of about 200 wpm. When the decoding process was isolated, RR approached values of 1200 wpm. When the number of stimuli exceeded the short-term memory span, RR decreased to 800 wpm. The semantic context contributed to reading speed only by a factor of 1.4. Finally, eye movements imposed an upper limit on RR (around 300 wpm). Overall, data indicate a speed limit of 300 wpm, which corresponds to the time needed for eye movement execution, i.e., the most time consuming mechanism. Results reconcile differences in reading rates reported by different laboratories and thus provide suggestions for targeting different components of reading rate.
Lorenz, Ralph D
2010-05-12
The 'two-box model' of planetary climate is discussed. This model has been used to demonstrate consistency of the equator-pole temperature gradient on Earth, Mars and Titan with what would be predicted from a principle of maximum entropy production (MEP). While useful for exposition and for generating first-order estimates of planetary heat transports, it has too low a resolution to investigate climate systems with strong feedbacks. A two-box MEP model agrees well with the observed day : night temperature contrast observed on the extrasolar planet HD 189733b.
High-speed laser modulation beyond the relaxation resonance frequency limit.
Sacher, Wesley D; Zhang, Eric J; Kruger, Brett A; Poon, Joyce K S
2010-03-29
We propose and show that for coupling modulated lasers (CMLs), in which the output coupler is modulated rather than the pump rate, the conventional relaxation resonance frequency limit to the laser modulation bandwidth can be circumvented. The modulation response is limited only by the coupler. Although CMLs are best suited to microcavities, as a proof-of-principle, a coupling-modulated erbium-doped fiber laser is modulated at 1 Gb/s, over 10000 times its relaxation resonance frequency.
Local Limit Phenomena, Flow Compression, and Fuel Cracking Effects in High-Speed Turbulent Flames
2015-06-01
dynamic adaptive hybrid integration, was developed for stiff chemistry. 15. SUBJECT TERMS chemical explosive mode analysis ( CEMA ...TECHNICAL DISCUSSION 1. Chemical explosive mode analysis ( CEMA ) for computational flame diagnostics The method of chemical explosive mode...analysis ( CEMA ) is a systematic approach to identify limit flame phenomena, including local ignition, extinction, and premixed and non- premixed reaction
Miller, Lee M; Kleidon, Axel
2016-11-29
Wind turbines generate electricity by removing kinetic energy from the atmosphere. Large numbers of wind turbines are likely to reduce wind speeds, which lowers estimates of electricity generation from what would be presumed from unaffected conditions. Here, we test how well wind power limits that account for this effect can be estimated without explicitly simulating atmospheric dynamics. We first use simulations with an atmospheric general circulation model (GCM) that explicitly simulates the effects of wind turbines to derive wind power limits (GCM estimate), and compare them to a simple approach derived from the climatological conditions without turbines [vertical kinetic energy (VKE) estimate]. On land, we find strong agreement between the VKE and GCM estimates with respect to electricity generation rates (0.32 and 0.37 We m(-2)) and wind speed reductions by 42 and 44%. Over ocean, the GCM estimate is about twice the VKE estimate (0.59 and 0.29 We m(-2)) and yet with comparable wind speed reductions (50 and 42%). We then show that this bias can be corrected by modifying the downward momentum flux to the surface. Thus, large-scale limits to wind power use can be derived from climatological conditions without explicitly simulating atmospheric dynamics. Consistent with the GCM simulations, the approach estimates that only comparatively few land areas are suitable to generate more than 1 We m(-2) of electricity and that larger deployment scales are likely to reduce the expected electricity generation rate of each turbine. We conclude that these atmospheric effects are relevant for planning the future expansion of wind power.
Limit of the speed-resolution properties in adiabatic supercritical fluid chromatography.
Gritti, Fabrice; Guiochon, Georges
2013-06-21
the column efficiency at high speeds. Eventually, for the same stationary phase and speed of analysis, SFC methods using pure CO2 may provide at least a twice column efficiency than LC methods using pure acetonitrile. For a constant pressure drop and resolution power, SFC methods may generate four times faster analyses than LC methods. Ultimately, a standard commercial 4.6mm × 50mm long column packed with 2.6 μm core-shell particles, operated with an inlet flow rate of 25 mL/min in fast SFC (200 bar back pressure, 40 °C) may provide a hold-up time of about 1s requiring data acquisition at a frequency of 400 Hz, with a variance of 0.35 μL(2). This performance will require the use of new, ultra-low dispersion SFC system.
Svendsen, Jon C; Tirsgaard, Bjørn; Cordero, Gerardo A; Steffensen, John F
2015-01-01
Intraspecific variation and trade-off in aerobic and anaerobic traits remain poorly understood in aquatic locomotion. Using gilthead sea bream (Sparus aurata) and Trinidadian guppy (Poecilia reticulata), both axial swimmers, this study tested four hypotheses: (1) gait transition from steady to unsteady (i.e., burst-assisted) swimming is associated with anaerobic metabolism evidenced as excess post exercise oxygen consumption (EPOC); (2) variation in swimming performance (critical swimming speed; U crit) correlates with metabolic scope (MS) or anaerobic capacity (i.e., maximum EPOC); (3) there is a trade-off between maximum sustained swimming speed (U sus) and minimum cost of transport (COTmin); and (4) variation in U sus correlates positively with optimum swimming speed (U opt; i.e., the speed that minimizes energy expenditure per unit of distance traveled). Data collection involved swimming respirometry and video analysis. Results showed that anaerobic swimming costs (i.e., EPOC) increase linearly with the number of bursts in S. aurata, with each burst corresponding to 0.53 mg O2 kg(-1). Data are consistent with a previous study on striped surfperch (Embiotoca lateralis), a labriform swimmer, suggesting that the metabolic cost of burst swimming is similar across various types of locomotion. There was no correlation between U crit and MS or anaerobic capacity in S. aurata indicating that other factors, including morphological or biomechanical traits, influenced U crit. We found no evidence of a trade-off between U sus and COTmin. In fact, data revealed significant negative correlations between U sus and COTmin, suggesting that individuals with high U sus also exhibit low COTmin. Finally, there were positive correlations between U sus and U opt. Our study demonstrates the energetic importance of anaerobic metabolism during unsteady swimming, and provides intraspecific evidence that superior maximum sustained swimming speed is associated with superior swimming
Jon Christian Svendsen
2015-02-01
Full Text Available Intraspecific variation and trade-off in aerobic and anaerobic traits remain poorly understood in aquatic locomotion. Using gilthead sea bream (Sparus aurata and Trinidadian guppy (Poecilia reticulata, both axial swimmers, this study tested four hypotheses: 1 gait transition from steady to unsteady (i.e. burst-assisted swimming is associated with anaerobic metabolism evidenced as excess post exercise oxygen consumption (EPOC; 2 variation in swimming performance (critical swimming speed; Ucrit correlates with metabolic scope (MS or anaerobic capacity (i.e. maximum EPOC; 3 there is a trade-off between maximum sustained swimming speed (Usus and minimum cost of transport (COTmin; and 4 variation in Usus correlates positively with optimum swimming speed (Uopt; i.e. the speed that minimizes energy expenditure per unit of distance travelled. Data collection involved swimming respirometry and video analysis. Results showed that anaerobic swimming costs (i.e. EPOC increase linearly with the number of bursts in S. aurata, with each burst corresponding to 0.53 mg O2 kg-1. Data are consistent with a previous study on striped surfperch (Embiotoca lateralis, a labriform swimmer, suggesting that the metabolic cost of burst swimming is similar across various types of locomotion. There was no correlation between Ucrit and MS or anaerobic capacity in S. aurata indicating that other factors, including morphological or biomechanical traits, influenced Ucrit. We found no evidence of a trade-off between Usus and COTmin. In fact, data revealed significant negative correlations between Usus and COTmin, suggesting that individuals with high Usus also exhibit low COTmin. Finally, there were positive correlations between Usus and Uopt. Our study demonstrates the energetic importance of anaerobic metabolism during unsteady swimming, and provides intraspecific evidence that superior maximum sustained swimming speed is associated with superior swimming economy and optimum
Svendsen, Jon C.; Tirsgaard, Bjørn; Cordero, Gerardo A.; Steffensen, John F.
2015-01-01
Intraspecific variation and trade-off in aerobic and anaerobic traits remain poorly understood in aquatic locomotion. Using gilthead sea bream (Sparus aurata) and Trinidadian guppy (Poecilia reticulata), both axial swimmers, this study tested four hypotheses: (1) gait transition from steady to unsteady (i.e., burst-assisted) swimming is associated with anaerobic metabolism evidenced as excess post exercise oxygen consumption (EPOC); (2) variation in swimming performance (critical swimming speed; Ucrit) correlates with metabolic scope (MS) or anaerobic capacity (i.e., maximum EPOC); (3) there is a trade-off between maximum sustained swimming speed (Usus) and minimum cost of transport (COTmin); and (4) variation in Usus correlates positively with optimum swimming speed (Uopt; i.e., the speed that minimizes energy expenditure per unit of distance traveled). Data collection involved swimming respirometry and video analysis. Results showed that anaerobic swimming costs (i.e., EPOC) increase linearly with the number of bursts in S. aurata, with each burst corresponding to 0.53 mg O2 kg−1. Data are consistent with a previous study on striped surfperch (Embiotoca lateralis), a labriform swimmer, suggesting that the metabolic cost of burst swimming is similar across various types of locomotion. There was no correlation between Ucrit and MS or anaerobic capacity in S. aurata indicating that other factors, including morphological or biomechanical traits, influenced Ucrit. We found no evidence of a trade-off between Usus and COTmin. In fact, data revealed significant negative correlations between Usus and COTmin, suggesting that individuals with high Usus also exhibit low COTmin. Finally, there were positive correlations between Usus and Uopt. Our study demonstrates the energetic importance of anaerobic metabolism during unsteady swimming, and provides intraspecific evidence that superior maximum sustained swimming speed is associated with superior swimming economy and
汽车电子自动限速系统的设计%The design of car electronic automated speed limit system
祝敏
2012-01-01
The paper introduces the car automated speed limit system based on MSP430F149 controller and NRF2401 wireless receive and dispatch chips. The system can set up aggregate speed limit number through the three kinds of parameters in road state, weather and car model. When entering different sections, the cars can automatically change speed limit number, but the drivers cannot do it. The system tests the present speed and compares it with speed limit number. When cars exceed the speed limit for 30S, the system sends out speeding language alarm prompt, controls automobile oil line, and keeps the speed near the speed limit number to automatically limit running speed of automobiles. All of these measures will greatly reduce traffic accidents.%文中介绍了以MSP430F149为控制器，以NRF2401为无线收发芯片的汽车自动限速系统。该系统能根据道路状况、天气、车型三种参数综合设定限速值，行车进入不同的路段，自动地改变限速值，司机无法更改。通过检测当前车速，并与限速值进行比较，当超速30S时，发出超速语言报警提示，并控制汽车油路，使车速保持在限速值附近，从而达到自动限制汽车行驶速度的目的。这将大大减少交通事故的发生。
Fault ride-through enhancement of fixed speed wind turbine using bridge-type fault current limiter
Mostafa I. Marei
2016-05-01
Full Text Available The interaction between wind energy turbines and the grid results in two main problems, increasing the short-circuit level and reducing the Fault Ride-Through (FRT capability during faults. The objective of this paper is to solve these problems, for fixed speed Wind Energy Systems (WECS, utilizing the bridge-type Fault Current Limiter (FCL with a discharging resistor. A simple cascaded control system is proposed for the FCL to regulate the terminal voltage of the generator and limit the current. The system is simulated on PSCAD/EMTDC software to evaluate the dynamic performance of the proposed WECS compensated by FCL. The simulation results show the potentials of the FCL as a simple and effective method for solving grid interconnection problems of WECS.
Kaiadi, Mehrzad; Tunestål, Per; Johansson, Bengt
2010-01-01
High EGR rates combined with turbocharging has been identified as a promising way to increase the maximum load and efficiency of heavy duty spark ignition Natural Gas engines. With stoichiometric conditions a three way catalyst can be used which means that regulated emissions can be kept at very low levels. Most of the heavy duty NG engines are diesel engines which are converted for SI operation. These engine's components are in common with the diesel-engine which put limits on higher exh...
A new limit on the light speed isotropy from the GRAAL experiment at the ESRF
Gurzadyan, V G; Beretta, M; Bocquet, J -P; D'Angelo, A; Di Salvo, R; Fantini, A; Franco, D; Gervino, G; Giardina, G; Ghio, F; Girolami, B; Giusa, A; Kashin, A; Khachatryan, H G; Knyazyan, S; Lapik, A; Sandri, P Levi; Lleres, A; Mammoliti, F; Mandaglio, G; Manganaro, M; Margarian, A; Mehrabyan, S; Messi, R; Moricciani, D; Nedorezov, V; Rebreyend, D; Russo, G; Rudnev, N; Schaerf, C; Sperduto, M -L; Sutera, M -C; Turinge, A; Vegna, V
2010-01-01
When the electrons stored in the ring of the European Synchrotron Radiation Facility (ESRF, Grenoble) scatter on a laser beam (Compton scattering in flight) the lower energy of the scattered electron spectra, the Compton Edge (CE), is given by the two body photon-electron relativistic kinematics and depends on the velocity of light. A precision measurement of the position of this CE as a function of the daily variations of the direction of the electron beam in an absolute reference frame provides a one-way test of Relativistic Kinematics and the isotropy of the velocity of light. The results of GRAAL-ESRF measurements improve the previously existing one-way limits, thus showing the efficiency of this method and the interest of further studies in this direction.
Comparative study on maximum residue limits standards of pesticides in peanuts%花生农药最大残留限量标准比对研究
丁小霞; 李培武; 周海燕; 李娟; 白艺珍
2011-01-01
It is important to protect the health of consumers and standardize the agricultural products in trading market. One essential aspect is to develop and implement a standardized scientific and applicable maximum residue limits( MRL) pesticides. A comparative study of maximum residue limits standards of pesticides in peanuts was carried out among China,Codex Alimentarius Commission (CAC) , Unite States, Japan and European Union. Corre-sponding suggestion was put forward after analyzing the problems in maximum residue limit standards of pesticides in China.%制定和实施科学合理的农药最大残留限量标准是保护消费者健康和规范农产品国际贸易的重要手段.对我国、国际食品法典委员会、花生主产国美国以及我国花生主要出口目的国日本和欧盟的花生农药最大残留限量标准进行了系统比较,分析了我国花生农药最大残留限量标准存在的问题,提出了相应的建议.
Sauer, T. [ebm-papst Mulfingen GmbH und Co. KG, Mulfingen (Germany)
2006-03-15
Blowers are often powered by rotary-current asynchronous motors with short-circuit rotors, which are robust, simple and reliable. Today, specifications have become more demanding. For example, economic efficiency and low noise - combined with speed control which again should be as simple as possible - are now required. Asynchronous motors are hardly capable of meeting these requirements, so they are being replaced in many applications by electronically commuted permanent magnet motors, so-called EC drives. (orig.)
Effect of two-qutrit entanglement on quantum speed limit time of a bipartite V-type open system
Behzadi, N., E-mail: n.behzadi@tabrizu.ac.ir [Research Institute for Fundamental Sciences, University of Tabriz (Iran, Islamic Republic of); Ahansaz, B.; Ektesabi, A.; Faizi, E. [Physics Department, Azarbaijan Shahid Madani University, Tabriz (Iran, Islamic Republic of)
2017-03-15
In the present paper, quantum speed limit (QSL) time of a bipartite V-type three-level atomic system under the effect of two-qutrit entanglement is investigated. Each party interacts with own independent reservoir. By considering two local unitarily equivalent Werner states and the Horodecki PPT state, as initial states, the QSL time is evaluated for each of them in the respective entangled regions. It is counterintuitively observed that the effect of entanglement on the QSL time driven from each of the initial Werner states are completely different when the degree of non-Markovianity is considerable. In addition, it is interesting that the effect of entanglement of the non-equivalent Horodecki state on the calculated QSL time displays an intermediate behavior relative to the cases obtained for the Werner states.
横风作用下高速列车安全运行速度限值的研究%Research on the Limited Safe Speed of a High-speed Train under Cross Wind
郗艳红; 毛军; 高亮; 杨国伟; 曲文强
2012-01-01
横风作用下的列车安全运行速度限值应通过列车气动特性和车辆轨道动力学特性的分析得到.以我国CRH3型高速列车实车为原型,考虑真实受电弓、转向架等列车的细部特征,假定列车在平地上行驶,对列车速度分别为200、250、300、350和380 km/h,横风速度分别为10、15、20、25和30 m/s,风向角为90°的25个工况进行气动特性的数值模拟,并采用国内实测轨道谱和德国轨道谱分别对这25个工况的车辆轨道动力学性能进行仿真计算和对比分析.结合国家标准和技术规范,给出CRH3型列车在平地上运行时,横风风速与列车最大安全运行速度之间的对应关系,为横风作用下的列车运行安全控制提供参考.%The limited safe speed of a high-speed train under crosswind should be obtained by analyzing the aerodynamic and vehicle-track dynamic characteristics. A real high-speed train of Type CRH3 was taken for case study. The train was assumed to run on a plane area under 25 numerically simulated operating conditions when the train speeds were chosen as 200,250,300,350 and 380 km/h,the crosswind velocities as 10,15,20,25 and 30m/s and the wind direction angle as 90° The detailed characteristics of real bogies and pantographs and so on were taken into account. The dynamic vehicle-track charateristics corresponding to the above 25 operating conditions were calculated respectively and compared in line with the domestic measured track spectra and the German track spectra. In accordance with the National standards and technical specifications concerned, the relationship between the crosswind velocity and the maximum safe operating speed of the CRH3 train running on a plane area was found. The results will play a guiding role in control of safe operation of a train under cross-wind.
Held, Louis F.; Pritchard, Ernest I.
1946-01-01
An investigation was conducted to evaluate the possibilities of utilizing the high-performance characteristics of triptane and xylidines blended with 28-R fuel in order to increase fuel economy by the use of high compression ratios and maximum-economy spark setting. Full-scale single-cylinder knock tests were run with 20 deg B.T.C. and maximum-economy spark settings at compression ratios of 6.9, 8.0, and 10.0, and with two inlet-air temperatures. The fuels tested consisted of triptane, four triptane and one xylidines blend with 28-R, and 28-R fuel alone. Indicated specific fuel consumption at lean mixtures was decreased approximately 17 percent at a compression ratio of 10.0 and maximum-economy spark setting, as compared to that obtained with a compression ratio of 6.9 and normal spark setting. When compression ratio was increased from 6.9 to 10.0 at an inlet-air temperature of 150 F, normal spark setting, and a fuel-air ratio of 0.065, 55-percent triptane was required with 28-R fuel to maintain the knock-limited brake power level obtained with 28-R fuel at a compression ratio of 6.9. Brake specific fuel consumption was decreased 17.5 percent at a compression ratio of 10.0 relative to that obtained at a compression ratio of 6.9. Approximately similar results were noted at an inlet-air temperature of 250 F. For concentrations up through at least 20 percent, triptane can be more efficiently used at normal than at maximum-economy spark setting to maintain a constant knock-limited power output over the range of compression ratios tested.
Take-off speed in jumping mantises depends on body size and a power-limited mechanism.
Sutton, G P; Doroshenko, M; Cullen, D A; Burrows, M
2016-07-15
Many insects such as fleas, froghoppers and grasshoppers use a catapult mechanism to jump, and a direct consequence of this is that their take-off velocities are independent of their mass. In contrast, insects such as mantises, caddis flies and bush crickets propel their jumps by direct muscle contractions. What constrains the jumping performance of insects that use this second mechanism? To answer this question, the jumping performance of the mantis Stagmomantis theophila was measured through all its developmental stages, from 5 mg first instar nymphs to 1200 mg adults. Older and heavier mantises have longer hind and middle legs and higher take-off velocities than younger and lighter mantises. The length of the propulsive hind and middle legs scaled approximately isometrically with body mass (exponent=0.29 and 0.32, respectively). The front legs, which do not contribute to propulsion, scaled with an exponent of 0.37. Take-off velocity increased with increasing body mass (exponent=0.12). Time to accelerate increased and maximum acceleration decreased, but the measured power that a given mass of jumping muscle produced remained constant throughout all stages. Mathematical models were used to distinguish between three possible limitations to the scaling relationships: first, an energy-limited model (which explains catapult jumpers); second, a power-limited model; and third, an acceleration -: limited model. Only the model limited by muscle power explained the experimental data. Therefore, the two biomechanical mechanisms impose different limitations on jumping: those involving direct muscle contractions (mantises) are constrained by muscle power, whereas those involving catapult mechanisms are constrained by muscle energy.
Take-off speed in jumping mantises depends on body size and a power-limited mechanism
Doroshenko, M.; Cullen, D. A.; Burrows, M.
2016-01-01
ABSTRACT Many insects such as fleas, froghoppers and grasshoppers use a catapult mechanism to jump, and a direct consequence of this is that their take-off velocities are independent of their mass. In contrast, insects such as mantises, caddis flies and bush crickets propel their jumps by direct muscle contractions. What constrains the jumping performance of insects that use this second mechanism? To answer this question, the jumping performance of the mantis Stagmomantis theophila was measured through all its developmental stages, from 5 mg first instar nymphs to 1200 mg adults. Older and heavier mantises have longer hind and middle legs and higher take-off velocities than younger and lighter mantises. The length of the propulsive hind and middle legs scaled approximately isometrically with body mass (exponent=0.29 and 0.32, respectively). The front legs, which do not contribute to propulsion, scaled with an exponent of 0.37. Take-off velocity increased with increasing body mass (exponent=0.12). Time to accelerate increased and maximum acceleration decreased, but the measured power that a given mass of jumping muscle produced remained constant throughout all stages. Mathematical models were used to distinguish between three possible limitations to the scaling relationships: first, an energy-limited model (which explains catapult jumpers); second, a power-limited model; and third, an acceleration-limited model. Only the model limited by muscle power explained the experimental data. Therefore, the two biomechanical mechanisms impose different limitations on jumping: those involving direct muscle contractions (mantises) are constrained by muscle power, whereas those involving catapult mechanisms are constrained by muscle energy. PMID:27284067
Grujicic, M.; Ramaswami, S.; Snipes, J. S.; Yavari, R.; Yen, C.-F.; Cheeseman, B. A.
2015-01-01
Our recently developed multi-physics computational model for the conventional gas metal arc welding (GMAW) joining process has been upgraded with respect to its predictive capabilities regarding the process optimization for the attainment of maximum ballistic limit within the weld. The original model consists of six modules, each dedicated to handling a specific aspect of the GMAW process, i.e., (a) electro-dynamics of the welding gun; (b) radiation-/convection-controlled heat transfer from the electric arc to the workpiece and mass transfer from the filler metal consumable electrode to the weld; (c) prediction of the temporal evolution and the spatial distribution of thermal and mechanical fields within the weld region during the GMAW joining process; (d) the resulting temporal evolution and spatial distribution of the material microstructure throughout the weld region; (e) spatial distribution of the as-welded material mechanical properties; and (f) spatial distribution of the material ballistic limit. In the present work, the model is upgraded through the introduction of the seventh module in recognition of the fact that identification of the optimum GMAW process parameters relative to the attainment of the maximum ballistic limit within the weld region entails the use of advanced optimization and statistical sensitivity analysis methods and tools. The upgraded GMAW process model is next applied to the case of butt welding of MIL A46100 (a prototypical high-hardness armor-grade martensitic steel) workpieces using filler metal electrodes made of the same material. The predictions of the upgraded GMAW process model pertaining to the spatial distribution of the material microstructure and ballistic limit-controlling mechanical properties within the MIL A46100 butt weld are found to be consistent with general expectations and prior observations.
Chen, Xi Lin; De Santis, Valerio; Umenei, Aghuinyue Esai
2014-07-07
In this study, the maximum received power obtainable through wireless power transfer (WPT) by a small receiver (Rx) coil from a relatively large transmitter (Tx) coil is numerically estimated in the frequency range from 100 kHz to 10 MHz based on human body exposure limits. Analytical calculations were first conducted to determine the worst-case coupling between a homogeneous cylindrical phantom with a radius of 0.65 m and a Tx coil positioned 0.1 m away with the radius ranging from 0.25 to 2.5 m. Subsequently, three high-resolution anatomical models were employed to compute the peak induced field intensities with respect to various Tx coil locations and dimensions. Based on the computational results, scaling factors which correlate the cylindrical phantom and anatomical model results were derived. Next, the optimal operating frequency, at which the highest transmitter source power can be utilized without exceeding the exposure limits, is found to be around 2 MHz. Finally, a formulation is proposed to estimate the maximum obtainable power of WPT in a typical room scenario while adhering to the human body exposure compliance mandates.
Blazevich, Anthony J; Horne, Sara; Cannavan, Dale
2008-01-01
knee extension training was performed 3 x week(-1) for 10 weeks. Maximal isometric strength (+11.2%) and RFD (measured from 0-30/50/100/200 ms, respectively; +10.5%-20.5%) increased after 10 weeks (P training mode. Peak EMG amplitude and rate of EMG rise......This study examined the effects of slow-speed resistance training involving concentric (CON, n = 10) versus eccentric (ECC, n = 11) single-joint muscle contractions on contractile rate of force development (RFD) and neuromuscular activity (EMG), and its maintenance through detraining. Isokinetic...... were not significantly altered with training or detraining. Subjects with below-median normalized RFD (RFD/MVC) at 0 weeks significantly increased RFD after 5- and 10-weeks training, which was associated with increased neuromuscular activity. Subjects who maintained their higher RFD after detraining...
高速公路不同路况下的安全限速%Safely-Limited Speeds on High Way in Different Road Conditions
冯涛; 李迅; 丁德平; 谢庄
2012-01-01
不同气象条件导致道面状况差异很大,为了提高不同道面状况条件下高速公路行车的安全性,从气象条件出发分析了干、湿、积雪、积冰道面条件对道路交通安全的影响,采用数学方法,以制动反应时间内行驶距离与制动距离之和小于能见距离为条件,推导了不同道面条件下的基于安全距离的高速公路最高车速限制值计算公式.利用双指数模型的纵向附着系数计算模型计算了附着系数,得出了不同道面条件下对应不同能见距离、附着系数的安全车速,为高影响天气条件下交通管理部门管理高速公路安全运行提供科学依据.%Different meteorological conditions lead to different road surface conditions. In order to increase the safety level of driving on the different road conditions on high way, from the view of meteorological conditions, the influences of different road conditions, such as dry, wet, snow and ice on road traffic safety are analyzed. Using the method of the mathematical method, under the condition that the sum of running distance and braking distance is less than the visible distance, the calculation formulas of the maximum speed limits on the different road conditions on the high way are derived based on the safe distance. The dual-exponential model is used to evaluate the longitudinal road friction coefficient, and the values of the corresponding safely-limited speeds are computed according to different visible distance and road fiction coefficients.
33 CFR 162.138 - Connecting waters from Lake Huron to Lake Erie; speed rules.
2010-07-01
... speed not greater than— (i) 12 statute miles per hour (10.4 knots) between Fort Gratiot Light and St... to Lake Erie; speed rules. 162.138 Section 162.138 Navigation and Navigable Waters COAST GUARD... REGULATIONS § 162.138 Connecting waters from Lake Huron to Lake Erie; speed rules. (a) Maximum speed limit...
James, Peter; Ito, Kate; Banay, Rachel F; Buonocore, Jonathan J; Wood, Benjamin; Arcaya, Mariana C
2014-01-01
Decreasing traffic speeds increases the amount of time drivers have to react to road hazards, potentially averting collisions, and makes crashes that do happen less severe. Boston's regional planning agency, the Metropolitan Area Planning Council (MAPC), in partnership with the Massachusetts Department of Public Health (MDPH), conducted a Health Impact Assessment (HIA) that examined the potential health impacts of a proposed bill in the state legislature to lower the default speed limits on local roads from 30 miles per hour (mph) to 25 mph. The aim was to reduce vehicle speeds on local roads to a limit that is safer for pedestrians, cyclists, and children. The passage of this proposed legislation could have had far-reaching and potentially important public health impacts. Lower default speed limits may prevent around 18 fatalities and 1200 serious injuries to motorists, cyclists and pedestrians each year, as well as promote active transportation by making local roads feel more hospitable to cyclists and pedestrians. While a lower speed limit would increase congestion and slightly worsen air quality, the benefits outweigh the costs from both a health and economic perspective and would save the state approximately $62 million annually from prevented fatalities and injuries.
Maximum Likelihood Identification of Nonlinear Model for High-speed Train%高速列车非线性模型的极大似然辨识
衷路生; 李兵; 龚锦红; 张永贤; 祝振敏
2014-01-01
提出高速列车非线性模型的极大似然(Maximum likelihood, ML)辨识方法,适合于高速列车在非高斯噪声干扰下的非线性模型的参数估计.首先,构建了描述高速列车单质点力学行为的随机离散非线性状态空间模型,并将高速列车参数的极大似然(ML)估计问题转化为期望极大(Expectation maximization,EM)的优化问题;然后,给出高速列车状态估计的粒子滤波器和粒子平滑器的设计方法,据此构造列车的条件数学期望,并给出最大化该数学期望的梯度搜索方法,进而得到列车参数的辨识算法,分析了算法的收敛速度;最后,进行了高速列车阻力系数估计的数值对比实验.结果表明,所提出的辨识方法的有效性.
李娟; 张克兆; 李生权; 刘超
2015-01-01
Considering the permanent magnet synchronous wind generator system with uncertainties, multi interferences and low efficiency, a maximum power point tracking with active disturbance rejection control strategy based on the best tip speed ratio was proposed to track the motor speed real time and to capture the maximum power. The active disturbance rejection controller does not depend on the mathematical model of the system. The uncertainties including nonlinear, strong coupling, parameter variations and ex-ternal disturbances wer lumped to the total disturbances of system, which affect the tracking speed in real time. The extended state observer estimates the total disturbances, and then compensates them through the feedback controller, which improves the speed tracking ability. Simulation results show that, com-pared with the traditional PI control method, the proposed control strategy not only guarantees the system to achieve maximum power output, but also has strong robustness against uncertain dynamics and external disturbances.%针对永磁同步风力发电系统中存在的不确定、多干扰、效率低等问题,提出一种以实现最大功率跟踪控制为目标,实时跟踪电机转速的基于最佳叶尖速比的自抗扰控制策略. 该方法不依赖于系统数学模型,将永磁同步风力发电机存在的、影响转速难以实时跟踪的非线性、强耦合、参数变化、外界干扰等不确定性看成系统总干扰. 通过扩张状态观测器对系统的总干扰进行估计,然后通过反馈控制器进行干扰补偿,从而提高转速的跟踪能力. 仿真结果表明,与传统的PI控制方法相比,自抗扰控制不仅能保证系统实现最大功率输出,而且提高了系统的鲁棒性和抗干扰性能.
孔新红; 马中元; 彭王敏子
2012-01-01
Based on meteorological data of five stations in Jiran, Yongxin, Wanr an, Suichuan and Taihe from 1970 to 2009, the weather systemthat produced the annual maximum wind speed of the nuclear power station areas is analyzed by using statistical methods. The results show that: before 90s, the annual maximum wind speed of Wanan nuclear power plant area is in 15 m/s or so, after that, it downs to 12 m/s. Since each station has its own records, the annual maximum wind speed shows a decreasing tendency and this trend is more apparent after the 90s. According to sample statistics of 208 times annual maximum wind speed in 40 years, the weather in regional area can be divided into four types: strong convective wind (48. 1%), cold winds (21. 2%), tropical cyclone and seat circulation winds (16.8) and other wind (13.9). The annual maximum wind speed appears in spring and summer, which is caused by strong convective weather, cold air, tropical cyclone and the typhoon heads and the other weather systems.%使用1970～2009年吉安、永新、万安、遂川和泰和五站气象资料,对核电站区域年最大风速及产生最大风速的天气系统,采用统计学方法和个例分析方法进行研究,结果表明：90年代前,万安核电站区域年最大风速在15m/s左右,90年代后,降至12m/s左右;各站自有记录以来,年最大风速表现呈缓慢降低的趋势,且从90年代后这种趋势更加明显。40a的208次最大风速样本统计表明,区域内影响天气可分为强对流天气大风（48.1%）、冷空气大风（21.2%）、热带气旋及台前环流大风（16.8）和其他大风（13.9）4种类型。年最大风速主要出现在春季和夏季,依次由强对流天气、冷空气、热带气旋及台前和其他天气系统影响所致。
Rama, Aarti; Kesari, Shreekant; Das, Pradeep; Kumar, Vijay
2017-07-24
Extensive application of routine insecticide i.e., dichlorodiphenyltrichloroethane (DDT) to control Phlebotomus argentipes (Diptera: Psychodidae), the proven vector of visceral leishmaniasis in India, had evoked the problem of resistance/tolerance against DDT, eventually nullifying the DDT dependent strategies to control this vector. Because tolerating an hour-long exposure to DDT is not challenging enough for the resistant P. argentipes, estimating susceptibility by exposing sand flies to insecticide for just an hour becomes a trivial and futile task.Therefore, this bioassay study was carried out to investigate the maximum limit of exposure time to which DDT resistant P. argentipes can endure the effect of DDT for their survival. The mortality rate of laboratory-reared DDT resistant strain P. argentipes exposed to DDT was studied at discriminating time intervals of 60 min and it was concluded that highly resistant sand flies could withstand up to 420 min of exposure to this insecticide. Additionally, the lethal time for female P. argentipes was observed to be higher than for males suggesting that they are highly resistant to DDT's toxicity. Our results support the monitoring of tolerance limit with respect to time and hence points towards an urgent need to change the World Health Organization's protocol for susceptibility identification in resistant P. argentipes.
Potvin, Jean; Goldbogen, Jeremy A; Shadwick, Robert E
2012-01-01
Bulk-filter feeding is an energetically efficient strategy for resource acquisition and assimilation, and facilitates the maintenance of extreme body size as exemplified by baleen whales (Mysticeti) and multiple lineages of bony and cartilaginous fishes. Among mysticetes, rorqual whales (Balaenopteridae) exhibit an intermittent ram filter feeding mode, lunge feeding, which requires the abandonment of body-streamlining in favor of a high-drag, mouth-open configuration aimed at engulfing a very large amount of prey-laden water. Particularly while lunge feeding on krill (the most widespread prey preference among rorquals), the effort required during engulfment involve short bouts of high-intensity muscle activity that demand high metabolic output. We used computational modeling together with morphological and kinematic data on humpback (Megaptera noveaangliae), fin (Balaenoptera physalus), blue (Balaenoptera musculus) and minke (Balaenoptera acutorostrata) whales to estimate engulfment power output in comparison with standard metrics of metabolic rate. The simulations reveal that engulfment metabolism increases across the full body size of the larger rorqual species to nearly 50 times the basal metabolic rate of terrestrial mammals of the same body mass. Moreover, they suggest that the metabolism of the largest body sizes runs with significant oxygen deficits during mouth opening, namely, 20% over maximum VO2 at the size of the largest blue whales, thus requiring significant contributions from anaerobic catabolism during a lunge and significant recovery after a lunge. Our analyses show that engulfment metabolism is also significantly lower for smaller adults, typically one-tenth to one-half VO2|max. These results not only point to a physiological limit on maximum body size in this lineage, but also have major implications for the ontogeny of extant rorquals as well as the evolutionary pathways used by ancestral toothed whales to transition from hunting individual prey
Jean Potvin
Full Text Available Bulk-filter feeding is an energetically efficient strategy for resource acquisition and assimilation, and facilitates the maintenance of extreme body size as exemplified by baleen whales (Mysticeti and multiple lineages of bony and cartilaginous fishes. Among mysticetes, rorqual whales (Balaenopteridae exhibit an intermittent ram filter feeding mode, lunge feeding, which requires the abandonment of body-streamlining in favor of a high-drag, mouth-open configuration aimed at engulfing a very large amount of prey-laden water. Particularly while lunge feeding on krill (the most widespread prey preference among rorquals, the effort required during engulfment involve short bouts of high-intensity muscle activity that demand high metabolic output. We used computational modeling together with morphological and kinematic data on humpback (Megaptera noveaangliae, fin (Balaenoptera physalus, blue (Balaenoptera musculus and minke (Balaenoptera acutorostrata whales to estimate engulfment power output in comparison with standard metrics of metabolic rate. The simulations reveal that engulfment metabolism increases across the full body size of the larger rorqual species to nearly 50 times the basal metabolic rate of terrestrial mammals of the same body mass. Moreover, they suggest that the metabolism of the largest body sizes runs with significant oxygen deficits during mouth opening, namely, 20% over maximum VO2 at the size of the largest blue whales, thus requiring significant contributions from anaerobic catabolism during a lunge and significant recovery after a lunge. Our analyses show that engulfment metabolism is also significantly lower for smaller adults, typically one-tenth to one-half VO2|max. These results not only point to a physiological limit on maximum body size in this lineage, but also have major implications for the ontogeny of extant rorquals as well as the evolutionary pathways used by ancestral toothed whales to transition from hunting
Measures for speed management.
2009-01-01
Measures for speed management are essential for limiting the negative effects of driving too fast and at inappropriate speeds. To begin with, safe and credible speed limits need to be determined. Dynamic and variable speed limits that take into account the current circumstances, such as weather cond
Hvid, Lars G; Strotmeyer, Elsa S; Skjødt, Mathias; Magnussen, Line V; Andersen, Marianne; Caserotti, Paolo
2016-07-01
Incomplete voluntary muscle activation may contribute to impaired muscle mechanical function and physical function in older adults. Exercise interventions have been shown to increase voluntary muscle activation, although the evidence is sparse for mobility-limited older adults, particularly in association with physical function. This study examined the effects of 12weeks of power training on outcomes of voluntary muscle activation and gait speed in mobility-limited older adults from the Healthy Ageing Network of Competence (HANC) study. We included 37 older men and women with a usual gait speed of analysis: n=16 in the training group (TG: 12weeks of progressive high-load power training, 2 sessions per week; age: 82.3±1.3years, 56% women) and n=21 in the control group (CG: no interventions; age: 81.6±1.1years, 67% women). Knee extensor muscle thickness (ultrasonography), strength (isokinetic dynamometry), voluntary activation (interpolated twitch technique), and gait speed (2-min maximal walking test) were assessed at baseline and post-intervention. At baseline, TG and CG were comparable for all measures. Post-intervention, significant between-group changes (TG vs. CG; pgait speed (+0.12m/s), whereas the between-group change in muscle thickness was non-significant (+0.08cm). Improvements in voluntary muscle activation were associated with improvements in gait speed in TG (r=0.67, ppower training, and is associated with improved maximal gait speed. Incomplete voluntary muscle activation should be considered one of the key mechanisms influencing muscle mechanical function and gait speed in older adults.
Dodrill, Michael J.; Yackulic, Charles B.; Kennedy, Theodore A.; Haye, John W
2016-01-01
The cold and clear water conditions present below many large dams create ideal conditions for the development of economically important salmonid fisheries. Many of these tailwater fisheries have experienced declines in the abundance and condition of large trout species, yet the causes of these declines remain uncertain. Here, we develop, assess, and apply a drift-foraging bioenergetics model to identify the factors limiting rainbow trout (Oncorhynchus mykiss) growth in a large tailwater. We explored the relative importance of temperature, prey quantity, and prey size by constructing scenarios where these variables, both singly and in combination, were altered. Predicted growth matched empirical mass-at-age estimates, particularly for younger ages, demonstrating that the model accurately describes how current temperature and prey conditions interact to determine rainbow trout growth. Modeling scenarios that artificially inflated prey size and abundance demonstrate that rainbow trout growth is limited by the scarcity of large prey items and overall prey availability. For example, shifting 10% of the prey biomass to the 13 mm (large) length class, without increasing overall prey biomass, increased lifetime maximum mass of rainbow trout by 88%. Additionally, warmer temperatures resulted in lower predicted growth at current and lower levels of prey availability; however, growth was similar across all temperatures at higher levels of prey availability. Climate change will likely alter flow and temperature regimes in large rivers with corresponding changes to invertebrate prey resources used by fish. Broader application of drift-foraging bioenergetics models to build a mechanistic understanding of how changes to habitat conditions and prey resources affect growth of salmonids will benefit management of tailwater fisheries.
Brigham-Grette, J.; Gualtieri, L.M.; Glushkova, O.Y.; Hamilton, T.D.; Mostoller, D.; Kotov, A.
2003-01-01
The Pekulney Mountains and adjacent Tanyurer River valley are key regions for examining the nature of glaciation across much of northeast Russia. Twelve new cosmogenic isotope ages and 14 new radiocarbon ages in concert with morphometric analyses and terrace stratigraphy constrain the timing of glaciation in this region of central Chukotka. The Sartan Glaciation (Last Glacial Maximum) was limited in extent in the Pekulney Mountains and dates to ???20,000 yr ago. Cosmogenic isotope ages > 30,000 yr as well as non-finite radiocarbon ages imply an estimated age no younger than the Zyryan Glaciation (early Wisconsinan) for large sets of moraines found in the central Tanyurer Valley. Slope angles on these loess-mantled ridges are less than a few degrees and crest widths are an order of magnitude greater than those found on the younger Sartan moraines. The most extensive moraines in the lower Tanyurer Valley are most subdued implying an even older, probable middle Pleistocene age. This research provides direct field evidence against Grosswald's Beringian ice-sheet hypothesis. ?? 2003 Elsevier Science (USA). All rights reserved.
Cohen, S.A.; Hosea, J.C.; Timberlake, J.R.
1984-10-19
A limiter with a specially contoured front face is provided. The front face of the limiter (the plasma-side face) is flat with a central indentation. In addition, the limiter shape is cylindrically symmetric so that the limiter can be rotated for greater heat distribution. This limiter shape accommodates the various power scrape-off distances lambda p, which depend on the parallel velocity, V/sub parallel/, of the impacting particles.
Controlling speed and direction during interception: an affordance-based approach.
Bastin, Julien; Fajen, Brett R; Montagne, Gilles
2010-04-01
The coordination of direction and speed of self-motion when intercepting a target moving parallel to the ground plane was examined. Subjects viewed a computer-generated environment comprised of a textured ground plane and a moving target. Turning rate was controlled using a steering wheel and speed was controlled using a foot pedal. It was hypothesized that these two degrees of freedom would be coordinated such that the speed required to intercept the target (i.e., the ideal speed) would be maintained below the subject's maximum possible speed. As predicted, subjects turned toward the target when ideal speed was less than maximum speed and ahead of the target when ideal speed was greater than maximum speed. When behavior was compared across groups with different maximum speed capabilities, it was found that the ratio of ideal to maximum speed was invariant across groups at critical points of both steering and speed adjustments. Finally, subjects rapidly recalibrated to a sudden increase or decrease in maximum speed. The results suggest that actors coordinate steering and speed during interception in a way that takes into account the limits on their action capabilities. Discussion focuses on the role of calibration and the implications of the present findings for existing models of visually guided interception.
Graviton time delay and a speed limit for small black holes in Einstein-Gauss-Bonnet theory
Papallo, Giuseppe; Reall, Harvey S. [DAMTP, Centre for Mathematical Sciences, University of Cambridge, Wilberforce Road, Cambridge CB3 0WA (United Kingdom)
2015-11-17
Camanho, Edelstein, Maldacena and Zhiboedov have shown that gravitons can experience a negative Shapiro time delay, i.e. a time advance, in Einstein-Gauss-Bonnet theory. They studied gravitons propagating in singular “shock-wave” geometries. We study this effect for gravitons propagating in smooth black hole spacetimes. For a small enough black hole, we find that gravitons of appropriate polarisation, and small impact parameter, can experience time advance. Such gravitons can also exhibit a deflection angle less than π, characteristic of a repulsive short-distance gravitational interaction. We discuss problems with the suggestion that the time advance can be used to build a “time machine”. In particular, we argue that a small black hole cannot be boosted to a speed arbitrarily close to the speed of light, as would be required in such a construction.
Graviton time delay and a speed limit for small black holes in Einstein-Gauss-Bonnet theory
Papallo, Giuseppe
2015-01-01
Camanho, Edelstein, Maldacena and Zhiboedov have shown that gravitons can experience a negative Shapiro time delay, i.e. a time advance, in Einstein-Gauss-Bonnet theory. They studied gravitons propagating in singular "shock-wave" geometries. We study this effect for gravitons propagating in smooth black hole spacetimes. For a small enough black hole, we find that gravitons of appropriate polarisation, and small impact parameter, can experience time advance. Such gravitons can also exhibit a deflection angle less than $\\pi$, characteristic of a repulsive short-distance gravitational interaction. We discuss problems with the suggestion that the time advance can be used to build a "time machine". In particular, we argue that a small black hole cannot be boosted to a speed arbitrarily close to the speed of light, as would be required in such a construction.
Graviton time delay and a speed limit for small black holes in Einstein-Gauss-Bonnet theory
Papallo, Giuseppe; Reall, Harvey S.
2015-11-01
Camanho, Edelstein, Maldacena and Zhiboedov have shown that gravitons can experience a negative Shapiro time delay, i.e. a time advance, in Einstein-Gauss-Bonnet theory. They studied gravitons propagating in singular "shock-wave" geometries. We study this effect for gravitons propagating in smooth black hole spacetimes. For a small enough black hole, we find that gravitons of appropriate polarisation, and small impact parameter, can experience time advance. Such gravitons can also exhibit a deflection angle less than π, characteristic of a repulsive short-distance gravitational interaction. We discuss problems with the suggestion that the time advance can be used to build a "time machine". In particular, we argue that a small black hole cannot be boosted to a speed arbitrarily close to the speed of light, as would be required in such a construction.
Suphan Sodsoon
2014-06-01
Full Text Available This study aims to solve a Vehicle Routing Problem with Time Windows and Speed Limits (VRPTWSL, which has received considerable attention in recent years. The vehicle routing problem with time windows is an extension of the well-known Vehicle Routing Problem (VRP and involves a fleet of vehicles set of from a depot to serve a number of customers at different geographic locations with various demands within specific time and speed limits before returning to the depot eventually. To solve the problem, an efficient Saving Method-Max Min Ant System (Saving-MMAS with Local Search algorithm is applied. Using minimization of the total transportation costs as the objective of the extension VRPTWSL, a mathematic model is constructed. Finally, the Saving-MMAS algorithms indicated the good quality of the method in this problem.
Beltrán, M C; Romero, T; Althaus, R L; Molina, M P
2013-05-01
The Charm maximum residue limit β-lactam and tetracycline test (Charm MRL BLTET; Charm Sciences Inc., Lawrence, MA) is an immunoreceptor assay utilizing Rapid One-Step Assay lateral flow technology that detects β-lactam or tetracycline drugs in raw commingled cow milk at or below European Union maximum residue levels (EU-MRL). The Charm MRL BLTET test procedure was recently modified (dilution in buffer and longer incubation) by the manufacturers to be used with raw ewe and goat milk. To assess the Charm MRL BLTET test for the detection of β-lactams and tetracyclines in milk of small ruminants, an evaluation study was performed at Instituto de Ciencia y Tecnologia Animal of Universitat Politècnica de València (Spain). The test specificity and detection capability (CCβ) were studied following Commission Decision 2002/657/EC. Specificity results obtained in this study were optimal for individual milk free of antimicrobials from ewes (99.2% for β-lactams and 100% for tetracyclines) and goats (97.9% for β-lactams and 100% for tetracyclines) along the entire lactation period regardless of whether the results were visually or instrumentally interpreted. Moreover, no positive results were obtained when a relatively high concentration of different substances belonging to antimicrobial families other than β-lactams and tetracyclines were present in ewe and goat milk. For both types of milk, the CCβ calculated was lower or equal to EU-MRL for amoxicillin (4 µg/kg), ampicillin (4 µg/kg), benzylpenicillin (≤ 2 µg/kg), dicloxacillin (30 µg/kg), oxacillin (30 µg/kg), cefacetrile (≤ 63 µg/kg), cefalonium (≤ 10 µg/kg), cefapirin (≤ 30 µg/kg), desacetylcefapirin (≤ 30 µg/kg), cefazolin (≤ 25 µg/kg), cefoperazone (≤ 25 µg/kg), cefquinome (20 µg/kg), ceftiofur (≤ 50 µg/kg), desfuroylceftiofur (≤ 50µg/kg), and cephalexin (≤ 50 µg/kg). However, this test could neither detect cloxacillin nor nafcillin at or below EU-MRL (CCβ >30 µg/kg). The
Kinkhabwala, Ali
2013-01-01
The most fundamental problem in statistics is the inference of an unknown probability distribution from a finite number of samples. For a specific observed data set, answers to the following questions would be desirable: (1) Estimation: Which candidate distribution provides the best fit to the observed data?, (2) Goodness-of-fit: How concordant is this distribution with the observed data?, and (3) Uncertainty: How concordant are other candidate distributions with the observed data? A simple unified approach for univariate data that addresses these traditionally distinct statistical notions is presented called "maximum fidelity". Maximum fidelity is a strict frequentist approach that is fundamentally based on model concordance with the observed data. The fidelity statistic is a general information measure based on the coordinate-independent cumulative distribution and critical yet previously neglected symmetry considerations. An approximation for the null distribution of the fidelity allows its direct conversi...
Zu, Penghe; Chen, Long; Xin, Jack
2015-09-01
The minimal speeds (c∗) of the Kolmogorov-Petrovsky-Piskunov (KPP) fronts at small diffusion (ɛ ≪ 1) in a class of time-periodic cellular flows with chaotic streamlines is investigated in this paper. The variational principle of c∗ reduces the computation to that of a principle eigenvalue problem on a periodic domain of a linear advection-diffusion operator with space-time periodic coefficients and small diffusion. To solve the advection dominated time-dependent eigenvalue problem efficiently over large time, a combination of spectral methods and finite element, as well as the associated fast solvers, are utilized to accelerate computation. In contrast to the scaling c∗ = O(ɛ 1 / 4) in steady cellular flows, a new relation c∗ = O(1) as ɛ ≪ 1 is revealed in the time-periodic cellular flows due to the presence of chaotic streamlines. Residual propagation speed emerges from the Lagrangian chaos which is quantified as a sub-diffusion process.
基于Vissim的高速公路隧道限速分析%Analysis of Highway Tunnel Speed Limit Based on Vissim
吴芮; 张道文; 陈奇; 王鑫
2015-01-01
To ensure that the best traffic efficiency as the basis of speed limit under the premise of tun-nel traffic safety, the process of the driving behavior of drivers through the tunnel was analyzed, and the key parameters were calibrated. A traffic simulation model of a highway tunnel and its passageway was established based on Vissim simulation software. Under the different traffic volume and speed, the run-ning state of the vehicle was observed. On the basis of satisfying peak traffic volume, the speed under the optimal traffic volume was selected, and according to the corresponding requirements of highway 's curve radius and design of ultra-highway, the reasonableness of the highway tunnel speed limit value was verified by traffic simulation.%以确保隧道交通安全前提下的最佳通行效率作为限速的依据,分析了驾驶人通过隧道的驾驶行为过程,标定了关键的驾驶行为参数.基于Vissim仿真软件,建立了某高速公路隧道及出入口的交通仿真模型,观察不同车流量和车速下,车辆的运行状态.在满足高峰流量的基础上,选择最优车流量下的车速,并根据高速公路圆曲线半径与超高的设计对应要求,通过交通仿真验证了高速公路隧道限速值的合理性.
Sevanto, S.; McDowell, N. G.; Dickman, L. T.; Pangle, R.; Pockman, W.
2011-12-01
Understanding the mechanisms behind tree mortality is increasingly important because climate change appears to be increasing drought severity and duration worldwide, with concomitant increases in mortality. Carbon starvation is one of the mechanisms suggested to be responsible for mortality, especially for species that close stomata at low xylem water tensions. Such plants would be under negative carbon balance during drought. Carbohydrate transport in plants relies on the availability of apoplastic water and therefore, shortage of water could lead to inability to distribute sugars and speed up carbon starvation even if carbohydrate reserves existed. To test these ideas we conducted a greenhouse study where pinon pine (Pinus edulis) trees were killed using two treatments: water limitation (complete drought) and carbon limitation (complete darkness). We collected tissue samples for non-structural carbohydrate content analysis weekly and monitored changes in xylem and phloem water potentials using stem diameter variation measurements. To follow changes in the physiological status of the trees we measured shoot gas exchange, leaf water potential and sap flow rate. Carbon-limited trees continued respiring at relatively high rates and maintained both xylem and phloem transport despite rapidly diminishing carbohydrate pools. Water-limited trees, on the other hand, exhibited reduced respiration and xylem and phloem transport rates as soon as drought inhibited stomatal opening; even before any significant drop in leaf water potential. This suggests that respirationmetabolic rate is strongly controlled by soil water availability, and instead of speeding up mortality, reduced carbohydrate transport and utilization rate may be a valuable strategy to enhance tree survival during long droughts.
COMPARISON BETWEEN FORMULAS OF MAXIMUM SHIP SQUAT
PETRU SERGIU SERBAN
2016-06-01
Full Text Available Ship squat is a combined effect of ship’s draft and trim increase due to ship motion in limited navigation conditions. Over time, researchers conducted tests on models and ships to find a mathematical formula that can define squat. Various forms of calculating squat can be found in the literature. Among those most commonly used are of Barrass, Millward, Eryuzlu or ICORELS. This paper presents a comparison between the squat formulas to see the differences between them and which one provides the most satisfactory results. In this respect a cargo ship at different speeds was considered as a model for maximum squat calculations in canal navigation conditions.
Heemstra de Groot, S.M.; Herrmann, O.E.
1990-01-01
An algorithm based on an alternative scheduling approach for iterative acyclic and cyclid DFGs (data-flow graphs) with limited resources that exploits inter- and intra-iteration parallelism is presented. The method is based on guiding the scheduling algorithm with the information supplied by a
Odden, Michelle C; Peralta, Carmen A; Berlowitz, Dan R; Johnson, Karen C; Whittle, Jeffrey; Kitzman, Dalane W; Beddhu, Srinivasan; Nord, John W; Papademetriou, Vasilios; Williamson, Jeff D; Pajewski, Nicholas M
2017-04-01
Intensive blood pressure (BP) control confers a benefit on cardiovascular morbidity and mortality; whether it affects physical function outcomes is unknown. To examine the effect of intensive BP control on changes in gait speed and mobility status. This randomized, clinical trial included 2636 individuals 75 years or older with hypertension and no history of type 2 diabetes or stroke who participated in the Systolic Blood Pressure Intervention Trial (SPRINT). Data were collected from November 8, 2010, to December 1, 2015. Analysis was based on intention to treat. Participants were randomized to intensive treatment with a systolic BP target of less than 120 mm Hg (n = 1317) vs standard treatment with a BP target of less than 140 mm Hg (n = 1319). Gait speed was measured using a 4-m walk test. Self-reported information concerning mobility was obtained from items on the Veterans RAND 12-Item Health Survey and the EQ-5D. Mobility limitation was defined as a gait speed less than 0.6 meters per second (m/s) or self-reported limitations in walking and climbing stairs. Among the 2629 participants in whom mobility status could be defined (996 women [37.9%]; 1633 men [62.1%]; mean [SD] age, 79.9 [4.0] years), median (interquartile range) follow-up was 3 (2-3) years. No difference in mean gait speed decline was noted between the intensive- and standard-treatment groups (mean difference, 0.0004 m/s per year; 95% CI, -0.005 to 0.005; P = .88). No evidence of any treatment group differences in subgroups defined by age, sex, race or ethnicity, baseline systolic BP, chronic kidney disease, or a history of cardiovascular disease were found. A modest interaction was found for the Veterans RAND 12-Item Health Survey Physical Component Summary score, although the effect did not reach statistical significance in either subgroup, with mean differences of 0.004 (95% CI, -0.002 to 0.010) m/s per year among those with scores of at least 40 and -0.008 (95% CI, -0.016 to 0
Hyuma Makizako
2015-03-01
Full Text Available Our aim was to determine whether baseline measures of cognitive functioning, walking speed, and depressive status are independent predictors of limitations in instrumental activities of daily living (IADL in older adults. The cross-sectional study involved 1329 community-dwelling adults, aged 75 years or older. At baseline, the Mini-Mental State Examination (MMSE, Symbol Digit Substitution Test (SDST, Geriatric Depressive Scale (GDS, and a word list memory task were completed, and self-reported IADLs and walking speed were recorded. The longitudinal study involved 948 participants without baseline IADL limitation, which was assessed at baseline and 15-month follow up, using the three Kihon Checklist subitems. In cross-sectional analyses, participants with IADL limitation demonstrated greater GDS scores, slower walking speeds, and lower MMSE, word list memory task, and SDST (only for women scores relative to those without IADL limitation. In the longitudinal analyses, baseline walking speed (men: OR 0.98; women: OR 0.97, p < 0.05 and word list memory task scores (men: OR 0.84; women: OR 0.83, p < 0.05 in both sexes and SDST scores in women (OR 0.96, p = 0.04 were independent predictors of subsequent IADL limitation. Walking speed, memory, and processing speed may be independent predictors of IADL limitation in older adults.
Vector control structure of an asynchronous motor at maximum torque
Chioncel, C. P.; Tirian, G. O.; Gillich, N.; Raduca, E.
2016-02-01
Vector control methods offer the possibility to gain high performance, being widely used. Certain applications require an optimum control in limit operating conditions, as, at maximum torque, that is not always satisfied. The paper presents how the voltage and the frequency for an asynchronous machine (ASM) operating at variable speed are determinate, with an accent on the method that keeps the rotor flux constant. The simulation analyses consider three load types: variable torque and speed, variable torque and constant speed, constant torque and variable speed. The final values of frequency and voltage are obtained through the proposed control schemes with one controller using the simulation language based on the Maple module. The dynamic analysis of the system is done for the case with P and PI controller and allows conclusions on the proposed method, which can have different applications, as the ASM in wind turbines.
Police enforcement and driving speed.
2008-01-01
Speed limits are violated frequently in the Netherlands. As speed is an important factor in road crashes, the surveillance of driving speeds is one of the spearheads in the policy plans of the Dutch police. Different methods of speed enforcement have proved to be effective in reducing speed and cras
2010-01-01
... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Rotor speed. 27.1509 Section 27.1509... Rotor speed. (a) Maximum power-off (autorotation). The maximum power-off rotor speed must be established... minimum power-off rotor speed must be established so that it is not less than 105 percent of the...
2010-01-01
... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Rotor speed. 29.1509 Section 29.1509....1509 Rotor speed. (a) Maximum power-off (autorotation). The maximum power-off rotor speed must be... minimum power-off rotor speed must be established so that it is not less than 105 percent of the...
Effects of loading and size on maximum power output and gait characteristics in geckos.
Irschick, Duncan J; Vanhooydonck, Bieke; Herrel, Anthony; Andronescu, Anemone
2003-11-01
Stride length, stride frequency and power output are all factors influencing locomotor performance. Here, we first test whether mass-specific power output limits climbing performance in two species of geckos (Hemidactylus garnoti and Gekko gecko) by adding external loads to their bodies. We then test whether body size has a negative effect on mass-specific power output. Finally, we test whether loading affects kinematics in both gecko species. Lizards were induced to run vertically on a smooth wooden surface with loads of 0-200% of body mass (BM) in H. garnoti and 0-100% BM in G. gecko. For each stride, we calculated angular and linear kinematics (e.g. trunk angle, stride length), performance (maximum speed) and mean mass-specific power output per stride. The addition of increasingly large loads caused an initial increase in maximum mass-specific power output in both species, but for H. garnoti, mass-specific power output remained constant at higher loads (150% and 200% BM), even though maximum velocity declined. This result, in combination with the fact that stride frequency showed no evidence of leveling off as speed increased in either species, suggests that power limits maximum speed. In addition, the large gecko (G. gecko) produced significantly less power than the smaller H. garnoti, despite the fact that both species ran at similar speeds. This difference disappeared, however, when we recalculated power output based on higher maximum speeds for unloaded G. gecko moving vertically obtained by other researchers. Finally, the addition of external loads did not affect speed modulation in either species: both G. gecko and H. garnoti increase speed primarily by increasing stride frequency, regardless of loading condition. For a given speed, both species take shorter but more strides with heavier loads, but for a given load, G. gecko attains similar speeds to H. garnoti by taking longer but fewer strides.
Smooth torque speed characteristic of switched reluctance motors
Zeng, Hui; Chen, Zhe; Chen, Hao
2014-01-01
of the constraints of the supply voltage and peak current. Based on previous work that sought to expand the STO range, a scheme is developed in this study to determine the maximum smooth torque range at each speed. The relationship between the maximum smooth torque and speed is defined as the smooth torque speed......The torque ripple of switched reluctance motors (SRMs) is the main disadvantage that limits the industrial application of these motors. Although several methods for smooth-toque operation (STO) have been proposed, STO works well only within a certain torque and speed range because...... characteristics (STSC), a concept similar to torque speed characteristics (TSC). STSC can be utilized to evaluate torque utilization by comparing it with TSC. Thus, the concept benefits the special design of SRMs, especially for the generation of smooth torque. Furthermore, the torque sharing function (TSF...
High speed multiplier design using Decomposition Logic
Ramanathan Palaniappan
2009-01-01
Full Text Available The multiplier forms the core of a Digital Signal Processor and is a major source of power dissipation. Often, the multiplier forms the limiting factor for the maximum speed of operation of a Digital Signal Processor. Due to continuing integrating intensity and the growing needs of portable devices, low-power, high-performance design is of prime importance. A new technique of implementing a multiplier circuit using Decomposition Logic is proposed here which improves speed with very little increase in power dissipation when compared to tree structured Dadda multipliers. Tanner EDA was used for simulation in the TSMC 180nm technology.
Do speed cameras reduce speeding in urban areas?
Oliveira, Daniele Falci de; Friche, Amélia Augusta de Lima; Costa, Dário Alves da Silva; Mingoti, Sueli Aparecida; Caiaffa, Waleska Teixeira
2015-11-01
This observational study aimed to estimate the prevalence of speeding on urban roadways and to analyze associated factors. The sample consisted of 8,565 vehicles circulating in areas with and without fixed speed cameras in operation. We found that 40% of vehicles 200 meters after the fixed cameras and 33.6% of vehicles observed on roadways without speed cameras were moving over the speed limit (p cameras, more women drivers were talking on their cell phones and wearing seatbelts when compared to men (p < 0.05 for both comparisons), independently of speed limits. The results suggest that compliance with speed limits requires more than structural interventions.
包维民; 闫海峰; 习子文
2016-01-01
Reasonable downhill speed limit can not only guarantee the safety of the train,but also make full use of the capacity of the railways.In this paper,the variation of the braking material and the brake shoe pressure in the current TG/01 -2014 Railway Technical Management Rules is analyzed,and by considering the influences of common braking speed and emergency braking speed,the methods of resultant force analysis and piecewise accumulation are adopted,so that the downhill speed limit of a freight train running on the slopes of 2 1‰~33‰is worked out.The results show that when the service brake factor of the train is taken as 0.6:1 .downhill speed limit is determined by the emergency braking speed for ramps from 21‰ to 29‰,and the downhill speed limit decrease with the increase of slope,and the downhill speed limit reduces 1 km/h for each additional 1‰;2.when the slope is from 30‰to 33‰,the downhill speed limit is determined by the common braking speed,and the downhill speed limit decrease sharply with the increase of the slope,and the downhill speed limit reduces 10km/h for each additional 1‰.The research conclusions are of use for reference for the design of long and steep slopes on railway.%合理的下坡限速可以保证列车在长大下坡道上安全运行，并能充分发挥铁路的运输能力。文章分析了现行TG／01－2014《铁路技术管理规程》中制动摩擦材料及闸瓦压力的变化情况，综合考虑列车常用制动限速和紧急制动限速的影响，采用合力分析法和分段累加法，计算得出列车在21‰～33‰坡度下的下坡限速。研究发现当列车常用制动系数取为0.6时：（1）21‰～29‰坡道下的下坡限速由紧急制动限速决定，下坡限速值随坡度值的增加而递减，坡度每增加1‰，限速值减少1 km／h；（2）30‰～33‰坡度下的下坡限速由列车常用制动限速决定，下坡限速值随坡度值的增加而
YU SHUJUN
2010-01-01
In the wake of the global financial crisis, China has amazed the world with the speed of its economic recovery. But what has been even more surprising is the speed of its railway evolution. The unveiling of the 1,069-km Wuhan-Guangzhou High-speed Railway on December 26, 2009 pushed China's high-speed rail sys-tem-the total mileage, the average speed and the technology-to rank first in the world almost overnight.
Speed control at low wind speeds for a variable speed fixed pitch wind turbine
Rosmin, N.; Watson, S.J.; Tompson, M. [Loughborough Univ., Loughborough, Leicestershire (United Kingdom)
2010-03-09
The maximum power regulation below rated wind speed is regulated by changing the rotor/generator speed at large frequency range in a fixed pitch, variable speed, stall-regulated wind turbine. In order to capture the power at a maximum value the power coefficient is kept at maximum peak point by maintaining the tip speed ratio at its optimum value. The wind industry is moving from stall regulated fixed speed wind turbines to newer improved innovative versions with better reliability. While a stall regulated fixed pitch wind turbine is among the most cost-effective wind turbine on the market, its problems include noise, severe vibrations, high thrust loads and low power efficiency. Therefore, in order to improve such drawbacks, the rotation of the generator speed is made flexible where the rotation can be controlled in variable speed. This paper discussed the development of a simulation model which represented the behaviour of a stall regulated variable speed wind turbine at low wind speed control region by using the closed loop scalar control with adjustable speed drive. The paper provided a description of each sub-model in the wind turbine system and described the scalar control of the induction machine. It was concluded that by using a constant voltage/frequency ratio of the generator's stator side control, the generator speed could be regulated and the generator torque could be controlled to ensure the power coefficient could be maintained close to its maximum value. 38 refs., 1 tab., 10 figs.
Monitoring speed before and during a speed publicity campaign.
van Schagen, Ingrid; Commandeur, Jacques J F; Goldenbeld, Charles; Stipdonk, Henk
2016-12-01
Driving speeds were monitored during a period of 16 weeks encompassing different stages of an anti-speeding campaign in the Netherlands. This campaign targeted speed limit violations in built-up areas. The observation periods differed in terms of intensity and media used for the campaign. Small road-side radars, mounted in light poles, were used and registered the speeds on 20 locations in built-up areas. Speeds of over 10 million vehicles were measured. Ten locations had a posted speed limit of 50km/h; the other ten had a posted speed limit of 30km/h. Posters were placed at half of each group of locations to remind drivers of the speed limit. The average speed on the 50km/h roads was 46.2km/h, and 36.1km/h on the 30km/h roads. The average proportions of vehicles exceeding the speed limit were 33.3% and 70.1% respectively. For the 30km/h roads, the data shows differences in speed and speeding behaviour between the six distinguished observation periods, but overall these differences cannot be logically linked to the contents of the phases and, hence, cannot be explained as an effect of the campaign. The only exception was an effect of local speed limit reminders on the 30km/h roads. This effect, however, was temporary and had disappeared within a week.
The maximum residue limits and determination of pesticide residues in asparagus%芦笋中农药最大残留限量及检测方法研究进展
宋欢; 车兰兰; 林勤保; 王蓉珍
2012-01-01
总结了芦笋中常用农药及欧盟、日本、美国和我国对其最大残留限量规定，并对农药残留相关检测方法在芦笋等果蔬中的应用进行综述，以期为我国芦笋中农药残留检测和控制提供参考。%Common pesticides used in asparagus planting and the maximum residue limits （MRLs） of those in European Union,Japan,USA and China were summarized,and also the application of relevant determination methods of pesticide residues to asparagus ,vegetables and fruit were reviewed. The paper is aimed at providing reference for pesticide residue determination and controlling in Chinese asparagus field.
杨艳红; 姜兆兴; 赵敏
2015-01-01
食品中农药的最大残留限量(MRLs)是保障食品质量安全的重要立法依据，也是指导食品和农产品等生产的关键技术指标。MRLs的制定方法不仅影响农产品行业的持续发展，而且还对提高我国农产品行业的国际竞争力起到积极作用。本文简要介绍目前国内外 MRLs 标准的现状、涉及农药的种类以及制定农药最大残留限量的依据，概述了基于田间实验数据制定最大残留限量的方法，并且比较了国际上欧盟(EU)、北美自由贸易协定(NAFTA)成员国、经济合作与发展组织(OECD)及农药残留联席会议(JMPR)的限量制定方案。%Pesticide maximum residue limit is a critical legislative basis for food safety and a key technical indicator to instruct food and agro-products. The establishing methods for MRLs not only influence the sustainable development of agricultural industry, but also play an actively role on the improvement of international competitiveness of Chinese agricultural industry. The current situation and principles employed to establish maximum residue limits were briefly introduced in this paper. The methods derived from field trials were summarized for setting MRLs. Meanwhile, the calculation methods proposed by European Union (EU), members of North American Free Trade Agreement (NAFTA), Organization for Economic Cooperation and Development (OECD) and Joint Meeting of Pesticide Residues (JMPR) were compared.
朱玮; 王廷昌
2013-01-01
为确保列车安全通过既有线临时限速区段,综合应用射频识别、信息处理与控制、无线数据通信、地理信息系统(GIS)等技术,研发铁路既有线临时限速预警控制系统.在既有线临时限速区段前设置带有临时限速信息的射频标签,在机车上安装射频标签车底识别器和临时限速信息预警控制装置等车载设备.当列车接近临时限速区段时,车载设备自动读取和显示射频标签内的临时限速信息,并向列车司机发出临时限速的语音提示;当列车超速时,车载设备自动输出制动控制信号.为临时限速区段设置的限速信息可利用手持机读取和编辑,并通过其内置的无线通信模块传送到临时限速信息管理服务器,在基于GIS的地图上实时显示临时限速区段的设置情况.经实车试验表明,该系统实现了列车接近和通过既有线临时限速区段时地一车之问临时限速信息的实时自动传递和列车限速预警控制,满足设计和应用要求.%Early warning and control techniques on temporary speed limit setting for existing lines are developed with radio frequency identification,information processing and control,wireless data communication and GIS technique to insure train running safely through the temporary speed limit section of existing lines.RFID labels with the information of temporary speed limits are set before the temporary speed limit section of railway existing lines.Locomotives are furnished with RFID labels car identifiers,temporary speed limit control devices and other on-board devices.When trains approach temporary speed limit section,on-board devices will automatically read and display the information of temporary speed limits in RFID labels,also broadcast voice prompt to driver.On-board devices automatically send brake control signal as the train runs over speed.RFID information can be read and edited by hand-held reader,and transferred to RFID information
Automatic speed control of highway traffic
Klingman, E. E.
1973-01-01
Vehicle control system monitors all vehicles in its range, and automatically slows down speeding vehicles by activating governor in vehicle. System determines only maximum speed; speeds below maximum are controlled by vehicle operator. Loss of transmitted signal or activation of emergency over-ride will open fuel line and return control to operator.
14 CFR 23.1583 - Operating limitations.
2010-01-01
....1583 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... is equal to the available runway length. (6) The maximum zero wing fuel weight, where relevant, as... type flight tests, together with recommended entry speeds and any other associated limitations....
Lucas R. Nascimento
2012-04-01
Full Text Available OBJECTIVE: To evaluate the effects of different instructions for the assessment of maximum walking speed during the ten-meter walking test with chronic stroke subjects. METHODS: Participants were instructed to walk under four experimental conditions: (1 comfortable speed, (2 maximum speed (simple verbal command, (3 maximum speed (modified verbal command-"catch a bus" and (4 maximum speed (verbal command + demonstration. Participants walked three times in each condition and the mean time to cover the intermediate 10 meters of a 14-meter corridor was registered to calculate the gait speed (m/s. Repeated-measures ANOVAs, followed by planned contrasts, were employed to investigate differences between the conditions (α=5%. Means, standard deviations and 95% confidence intervals (CI were calculated. RESULTS: The mean values for the four conditions were: (1 0.74m/s; (2 0.85 m/s; (3 0.93 m/s; (4 0.92 m/s, respectively, with significant differences between the conditions (F=40.9; pOBJETIVO: Avaliar os efeitos de diferentes instruções para avaliação da velocidade de marcha máxima de indivíduos hemiparéticos durante o teste de caminhada de 10 metros. MÉTODOS: Os indivíduos deambularam em quatro condições experimentais: (1 velocidade habitual, (2 velocidade máxima (comando verbal simples, (3 velocidade máxima (comando verbal modificado: pegar ônibus, (4 velocidade máxima (comando verbal + demonstração. Solicitou-se a cada participante que deambulasse três vezes em cada condição, e a média do tempo necessário para percorrer os 10 metros intermediários de um corredor de 14 metros foi utilizada para cálculo da velocidade (m/s. A ANOVA de medidas repetidas, com contrastes pré-planejados, foi utilizada para comparação dos dados (α=5%, sendo apresentados valores de média, desvio-padrão e intervalos de confiança (IC de 95%. RESULTADOS: As médias de velocidade para as quatro condições foram: (1 0,74m/s; (2 0,85m/s; (3 0,93m/s; (4
赵明; 谢松梅; 杨劲; 魏敏吉
2014-01-01
During the assessment of bioequivalence in our country ,the in-terval limits for maximum concentration ( Cmax ) is in an alternating phase.The aim of this paper is to introduce some principles and thoughts of bioequivalence for area under the curve (AUC) and Cmax.Examples of two drugs evaluation were presented here , which might be helpful for the development and review of generics.%在国内的生物等效性评价中，峰浓度（Cmax ）的等效界值尚处在新老标准交替阶段。当 Cmax处在新老标准之间，如何进行审评决策，是一个需要认真考虑的问题。本文通过2个药物审评实例，介绍关于该类问题的思考原则和思路，以期为仿制药的研究开发和审评提供参考。
Brake Rating Selection and Running-speed Limit Investigation of Freight Train%货物列车制车率的选取与运行限速的探讨
曹兴贵
2011-01-01
通过计算分析,阐述了车轮保持制动过程中不产生滑行的条件,货物列车制动率的选取以及列车最高运行速度、紧急制动距离限值、制动率和轴重间的关系.阐明了轴重提高到25～30t后,制动距离限值不延长,必须降低列车最高运行速度；要保证货物列车最高运行速度,必须延长制动距离限值.%Based on calculation and analysis, the conditions of wheel keeping from sliding in brake, selection of freight train brake rating, and relations between train axle, the highest running speed, distance limit of emergency brake, and brake rating were expounded. It was pointed that the train highest running speed must be reduced when the axle load was increased to 25-301 without extending brake distance limit, on the other hand, the train brake distance limit must be extending to keep the highest running speed.
Pay as You Speed, ISA with incentives for not speeding
Lahrmann, Harry; Agerholm, Niels; Tradisauskas, Nerius
2012-01-01
The Intelligent Speed Adaptation (ISA) project we describe in this article is based on Pay as You Drive principles. These principles assume that the ISA equipment informs a driver of the speed limit, warns the driver when speeding and calculates penalty points. Each penalty point entails the redu...
Monitoring speed before and during a speed publicity campaign.
Schagen, I.N.L.G. van Commandeur, J.J.F. Goldenbeld, C. & Stipdonk, H.
2016-01-01
Driving speeds were monitored during a period of 16 weeks encompassing different stages of an anti-speeding campaign in the Netherlands. This campaign targeted speed limit violations in built-up areas. The observation periods differed in terms of intensity and media used for the campaign. Small road
Maximum Autocorrelation Factorial Kriging
Nielsen, Allan Aasbjerg; Conradsen, Knut; Pedersen, John L.
2000-01-01
This paper describes maximum autocorrelation factor (MAF) analysis, maximum autocorrelation factorial kriging, and its application to irregularly sampled stream sediment geochemical data from South Greenland. Kriged MAF images are compared with kriged images of varimax rotated factors from...
Abolishing the maximum tension principle
Dabrowski, Mariusz P
2015-01-01
We find the series of example theories for which the relativistic limit of maximum tension $F_{max} = c^2/4G$ represented by the entropic force can be abolished. Among them the varying constants theories, some generalized entropy models applied both for cosmological and black hole horizons as well as some generalized uncertainty principle models.
Abolishing the maximum tension principle
Mariusz P. Da̧browski
2015-09-01
Full Text Available We find the series of example theories for which the relativistic limit of maximum tension Fmax=c4/4G represented by the entropic force can be abolished. Among them the varying constants theories, some generalized entropy models applied both for cosmological and black hole horizons as well as some generalized uncertainty principle models.
Speed Variance and Its Influence on Accidents.
Garber, Nicholas J.; Gadirau, Ravi
A study was conducted to investigate the traffic engineering factors that influence speed variance and to determine to what extent speed variance affects accident rates. Detailed analyses were carried out to relate speed variance with posted speed limit, design speeds, and other traffic variables. The major factor identified was the difference…
20 CFR 229.48 - Family maximum.
2010-04-01
... month on one person's earnings record is limited. This limited amount is called the family maximum. The family maximum used to adjust the social security overall minimum rate is based on the employee's Overall..., when any of the persons entitled to benefits on the insured individual's compensation would, except...
Demonstration of variable speed permanent magnet generator at small, low-head hydro site
Brown Kinloch, David [Shaker Landing Hydro Associates, Inc., Louisville, KY (United States)
2015-12-18
Small hydro developers face a limited set of bad choices when choosing a generator for a small low-head hydro site. Direct drive synchronous generators are expensive and technically complex to install. Simpler induction generators are higher speed, requiring a speed increaser, which results in inefficiencies and maintenance problems. In addition, both induction and synchronous generators turn at a fixed speed, causing the turbine to run off its peak efficiency curve whenever the available head is different than the designed optimum head.The solution to these problems is the variable speed Permanent Magnet Generators (PMG). At the Weisenberger Mill in Midway, KY, a variable speed Permanent Magnet Generator has been installed and demonstrated. This new PMG system replaced an existing induction generator that had a HTD belt drive speed increaser system. Data was taken from the old generator before it was removed and compared to data collected after the PMG system was installed. The new variable speed PMG system is calculated to produce over 96% more energy than the old induction generator system during an average year. This significant increase was primarily due to the PMG generator operating at the correct speed at the maximum head, and the ability for the PMG generator to reduce its speed to lower optimum speeds as the stream flow increased and the net head decreased.This demonstration showed the importance of being able to adjust the speed of fixed blade turbines. All fixed blade turbines with varying net heads could achieve higher efficiencies if the speed can be matched to the optimum speed as the head changes. In addition, this demonstration showed that there are many potential efficiencies that could be realized with variable speed technology at hydro sites where mismatched turbine and generator speeds result in lower power output, even at maximum head. Funding for this project came from the US Dept. of Energy, through Award Number DE-EE0005429.
李太平
2012-01-01
Under the information asymmetry and market supervision lack of agri-food quality,the excessively rigorous standard of maximum residue limits（MRLs）for pesticide in agrifood is not only unbeneficial to protect consumer health and ecological environment,but also aggregate serious pesticide residues in agrifood.Taking national standard Maximum Residue Limits for Pesticides in Food（GB2763-2005）as a case,calculated the Theory Daily Intake（TDI）related agrifoods of 439 residue indexes of 126 pesticides with the quantity relation between MRLs,acceptable daily intake（ADI）and TDI,and compared with the customer＇s Real Daily Intake（RDI）related agrifoods.It was found that there were 111 residue indexes related agri-foods which TDI were overly above and beyond their RDI of Chinese residents,accounted for 23.22% of 478 pesticide residue indexes in this national standards.This evidence proved that the national standard had the excessively rigorous tendency really and suggested our government would revise this standard at once in order to eliminate the food safety management trap.%在农产品质量信息不对称、市场监管不到位的情况下,农药最大残留限量标准制定过严,不但不能保护消费者健康和农业生态环境,反而会加剧农产品的农药残留问题泛滥。利用农药最大残留限量（MRLs）、日允许摄入量（ADI）与被测食品每日最大理论摄入量（TDI）三者之间的数量关系,以《食品中农药最大残留限量》GB2763-2005为例,计算了126种农药439个残留指标的TDI值,发现有111个残留指标的TDI值远远大于我国居民每日实际摄入量（RDI）,占GB2763-2005国家标准478个残留限量指标的23.22%,表明我国农药最大残留限量国家标准部分指标值设定存在过严的倾向,建议政府尽快修订该标准,以消除食品安全管理隐患。
Comment on "Measurement of the speed-of-light perturbation of free-fall absolute gravimeters"
Nagornyi, V D
2014-01-01
The paper (Rothleitner et al. 2014 Metrologia 51, L9) reports on the measurement of the speed-of-light perturbation in absolute gravimeters. The conclusion that the perturbation reaches only 2/3 of the commonly accepted value violates the fundamental limitation on the maximum speed of information transfer. The conclusion was deluded by unaccounted parasitic perturbations, some of which are obvious from the report.
Hvid, Lars G; Strotmeyer, Elsa S; Skjødt, Mathias
2016-01-01
Incomplete voluntary muscle activation may contribute to impaired muscle mechanical function and physical function in older adults. Exercise interventions have been shown to increase voluntary muscle activation, although the evidence is sparse for mobility-limited older adults, particularly in as...
Variable speed limits control for freeway based on cell transmission model%基于元胞传输模型的高速公路可变限速控制
马明辉; 杨庆芳; 梁士栋
2015-01-01
In order to solve congestion problem on freeway during peak period ,which leads to increase of vehicle delays ,and drop of service level ,an optimization method was proposed for bottleneck re‐gion on freeway mainline based on cell transmission model .Variable speed limits control factors and cell transmission model were combined to describe real‐time traffic flow on freeway .Further ,the op‐timization variable speed limits control model at bottleneck region of freeway was formulated with the objective of improving traffic efficiency and decreasing vehicle delays .T he test results show that opti‐mization variable speed limits control method proposed could improve traffic operation efficiency and traffic order ,especially during congestion hours .%针对高速公路交通拥挤、整体服务水平降低、车辆延误增加等问题，提出了一种基于元胞传输模型的高速公路瓶颈区域可变限速控制方法。将可变限速控制方法同元胞传输模型进行融合，使其对限速条件下高速公路交通流变化进行描述，并以提高通行效率和缩短车辆平均延误为控制目标，建立了高速公路瓶颈区域可变限速最优控制模型。实验证明：在高流量条件下，基于元胞传输模型的高速公路可变限速控制方法具有良好的控制效果，能够有效地提升高速公路整体服务水平。
Maximum likelihood estimation of fractionally cointegrated systems
Lasak, Katarzyna
In this paper we consider a fractionally cointegrated error correction model and investigate asymptotic properties of the maximum likelihood (ML) estimators of the matrix of the cointe- gration relations, the degree of fractional cointegration, the matrix of the speed of adjustment...
Design of GPS-based speed-limiting and bus station announcement system for bus%基于GPS公交车限速报站系统设计
袁卫
2012-01-01
A vehicle-mounted system with C8051F040 MCU as the control core is designed based on GPS and used to realize automatic bus station announcement. Firstly, voice information of each station is recorded by a sound recording interface. The system automatically indentifies next station and reports the station name,while the bus is driving. At the same time, maximum of driving speed is set. Once the bus exceeds the set speed, the system completes the function of voice warning. In addition, the system has the function of accurate positioning and can operate day and night.%为实现公交车的自动报站功能,提出一种以C8051F040单片机和GPS卫星定位系统的设计方案.首先设置通过录音接口预存各站点具体位置的语音信息,当公交车在行驶时,能自动识别站点并完成语音报站功能,同时可设置公交车行驶的上限速度,当超过该速度值时,系统将完成语音报警提示.该系统定位准确,并可实现全天侯工作.
Bhatnagar, Shalabh
2017-01-01
Sound is an emerging source of renewable energy but it has some limitations. The main limitation is, the amount of energy that can be extracted from sound is very less and that is because of the velocity of the sound. The velocity of sound changes as per medium. If we could increase the velocity of the sound in a medium we would be probably able to extract more amount of energy from sound and will be able to transfer it at a higher rate. To increase the velocity of sound we should know the speed of sound. If we go by the theory of classic mechanics speed is the distance travelled by a particle divided by time whereas velocity is the displacement of particle divided by time. The speed of sound in dry air at 20 °C (68 °F) is considered to be 343.2 meters per second and it won't be wrong in saying that 342.2 meters is the velocity of sound not the speed as it's the displacement of the sound not the total distance sound wave covered. Sound travels in the form of mechanical wave, so while calculating the speed of sound the whole path of wave should be considered not just the distance traveled by sound. In this paper I would like to focus on calculating the actual speed of sound wave which can help us to extract more energy and make sound travel with faster velocity.
Rice, C.K.
2001-06-06
The ORNL Heat Pump Model and an optimizing program were used to explore the limits of steady-state heating efficiency for conventional air-source heat pumps. The method used allows for the simultaneous optimization of ten selected design variables, taking proper account of their interactions, while constraining other parameters to chosen limits or fixed values. Designs were optimized for a fixed heating capacity, but the results may be scaled to other capacities. Substantial performance improvement is predicted compared to today's state of the art heat pump. With increased component efficiencies that are expected in the near future and with modest increases in heat exchanger area, a 28% increase in heating efficiency is predicted; for long-term improvements with considerably larger heat exchangers, a 56% increase is possible. The improved efficiencies are accompanied by substantial reductions in the requirements for compressor and motor size. The predicted performance improvements are attributed not only to improved components and larger heat exchangers but also to the use of an optimizing design procedure. Deviations from the optimized design may be necessary to make use of available component sizes and to maintain good cooling-mode performance while improving the heating efficiency. Sensitivity plots (i.e., COP as a function of one or more design parameters) were developed to explore design flexibilities and to evaluate their consequences. The performance of the optimized designs was compared to that of modified ideal cycles to assess the factors that limit further improvement. It is hoped that the design methods developed will be useful to designers in the heat pump industry.
Maximum Autocorrelation Factorial Kriging
Nielsen, Allan Aasbjerg; Conradsen, Knut; Pedersen, John L.; Steenfelt, Agnete
2000-01-01
This paper describes maximum autocorrelation factor (MAF) analysis, maximum autocorrelation factorial kriging, and its application to irregularly sampled stream sediment geochemical data from South Greenland. Kriged MAF images are compared with kriged images of varimax rotated factors from an ordinary non-spatial factor analysis, and they are interpreted in a geological context. It is demonstrated that MAF analysis contrary to ordinary non-spatial factor analysis gives an objective discrimina...
Handley, Bill
2012-01-01
This new, revised edition of the bestselling Speed Mathematics features new chapters on memorising numbers and general information, calculating statistics and compound interest, square roots, logarithms and easy trig calculations. Written so anyone can understand, this book teaches simple strategies that will enable readers to make lightning-quick calculations. People who excel at mathematics use better strategies than the rest of us; they are not necessarily more intelligent. With Speed Mathematics you'll discover methods to make maths easy and fun. This book is perfect for stud
王磊; 林永杰
2016-01-01
以交通检测系统获取的车道流量和速度为模型输入，分别提出基于延误损失、事故损失和综合损失等3类步进式可变限速控制。综合现有基于流量和基于车速离散性算法估计了高速公路事故发生率，提出了基于延误和事故发生率的路段综合损失计算方法。以青兰高速莱芜区约20 km的路段为实例，模拟了8组可变限速牌，通过微观仿真验证了提出的3种算法。结果证明，相比于静态控制，建立的3种模型均显著降低了主线车流的停车次数、停车延误和综合延误，改善了车辆行驶的平稳性，但主线车辆旅行时间略有增加。根据敏感性分析发现，随着驾驶员对限速值服从率的下降，可变限速控制的效益也逐渐降低，尤其低于80%时，下降显著；当低于60%时，基本保持不变。%Taking traffic volume and speed collected by traffic detection system as input variables, this paper proposes three kinds of step-by-step variable speed limit control models to minimize estimated delay cost, crash cost and comprehensive cost, respectively. The freeway crash rate is estimated based on volume-over-capacity and speed deviation by the existing model, and then the comprehensive cost is computed in terms of estimated delay and crash rate. In tests that used field freeway from about 20km segment of Qing-lan freeway with eight variable speed limit signs, these developed three controls show promise in reducing the numbers of vehicle stops, stopped delay and equivalent travel delay based on micro simulation results, smoothing traffic speed and improving traffic safety. Nevertheless, travel time of freeway vehicles is increased a little. Additionally, sensitivity analysis of driver compliance rate indicates that benefits of variable speed limit are gradually reduced as compliance rate decreased. When the compliance rate is below 80%, benefits are significantly decreased;and benefits are
Hanford Site peak gust wind speeds
Ramsdell, J.V.
1998-09-29
Peak gust wind data collected at the Hanford Site since 1945 are analyzed to estimate maximum wind speeds for use in structural design. The results are compared with design wind speeds proposed for the Hanford Site. These comparisons indicate that design wind speeds contained in a January 1998 advisory changing DOE-STD-1020-94 are excessive for the Hanford Site and that the design wind speeds in effect prior to the changes are still appropriate for the Hanford Site.
The Testability of Maximum Magnitude
Clements, R.; Schorlemmer, D.; Gonzalez, A.; Zoeller, G.; Schneider, M.
2012-12-01
Recent disasters caused by earthquakes of unexpectedly large magnitude (such as Tohoku) illustrate the need for reliable assessments of the seismic hazard. Estimates of the maximum possible magnitude M at a given fault or in a particular zone are essential parameters in probabilistic seismic hazard assessment (PSHA), but their accuracy remains untested. In this study, we discuss the testability of long-term and short-term M estimates and the limitations that arise from testing such rare events. Of considerable importance is whether or not those limitations imply a lack of testability of a useful maximum magnitude estimate, and whether this should have any influence on current PSHA methodology. We use a simple extreme value theory approach to derive a probability distribution for the expected maximum magnitude in a future time interval, and we perform a sensitivity analysis on this distribution to determine if there is a reasonable avenue available for testing M estimates as they are commonly reported today: devoid of an appropriate probability distribution of their own and estimated only for infinite time (or relatively large untestable periods). Our results imply that any attempt at testing such estimates is futile, and that the distribution is highly sensitive to M estimates only under certain optimal conditions that are rarely observed in practice. In the future we suggest that PSHA modelers be brutally honest about the uncertainty of M estimates, or must find a way to decrease its influence on the estimated hazard.
大容量高速限流开关的设计与试验研究%Design and Test Study of Large Capacity High Speed Current Limit Switch
李健; 朱峰
2011-01-01
针对现有保护设备难以满足大容量电力系统短路保护要求的问题，研制了一种基于爆炸活塞式高速开断器和灭弧熔断器的混合型限流保护装置，设计了额定640V／2500A的工程样机，并进行了高速开断器的分断试验和整机的限流试验。试验结果表明，该保护装置限流效果显著，全分断时fHJ仪为2．5ms，大大提高了电力系统的安全性。%Aiming at the problem that the existing protection equipment is difficult to meet large capacity power system short circuit protective requirements problem, this paper researched a kind of high speed break-off device based on explosive piston type and arc blow-out fuse mixed type, current limit protection device, designing rated voltage 640 V/2 500 A engineering sample machine. The break-off test and whole machine current limit test were carried out for high speed breaker. Test result shows that the protective device current limit effect is obvious and the total break-offtime is only 2.5 ms, which greatly raises safety of the power system.
Hudson, Penny E; Corr, Sandra A; Wilson, Alan M
2012-07-15
The cheetah and racing greyhound are of a similar size and gross morphology and yet the cheetah is able to achieve a far higher top speed. We compared the kinematics and kinetics of galloping in the cheetah and greyhound to investigate how the cheetah can attain such remarkable maximum speeds. This also presented an opportunity to investigate some of the potential limits to maximum running speed in quadrupeds, which remain poorly understood. By combining force plate and high speed video data of galloping cheetahs and greyhounds, we show how the cheetah uses a lower stride frequency/longer stride length than the greyhound at any given speed. In some trials, the cheetahs used swing times as low as those of the greyhounds (0.2 s) so the cheetah has scope to use higher stride frequencies (up to 4.0 Hz), which may contribute to it having a higher top speed that the greyhound. Weight distribution between the animal's limbs varied with increasing speed. At high speed, the hindlimbs support the majority of the animal's body weight, with the cheetah supporting 70% of its body weight on its hindlimbs at 18 m s(-1); however, the greyhound hindlimbs support just 62% of its body weight. Supporting a greater proportion of body weight on a particular limb is likely to reduce the risk of slipping during propulsive efforts. Our results demonstrate several features of galloping and highlight differences between the cheetah and greyhound that may account for the cheetah's faster maximum speeds.
Dynamics of non-stationary processes that follow the maximum of the Rényi entropy principle.
Shalymov, Dmitry S; Fradkov, Alexander L
2016-01-01
We propose dynamics equations which describe the behaviour of non-stationary processes that follow the maximum Rényi entropy principle. The equations are derived on the basis of the speed-gradient principle originated in the control theory. The maximum of the Rényi entropy principle is analysed for discrete and continuous cases, and both a discrete random variable and probability density function (PDF) are used. We consider mass conservation and energy conservation constraints and demonstrate the uniqueness of the limit distribution and asymptotic convergence of the PDF for both cases. The coincidence of the limit distribution of the proposed equations with the Rényi distribution is examined.
冯国英; 包道日娜; 刘志璋; 范源
2009-01-01
The most difficult problem faced by a small-sized wind turbine generator is the assurance of reliability,i.e.speed limit-related protection problem when a gale takes place.From the standpoint of energy conservation,the authors have analyzed the feasibility of employing the power matching characteristics of a wind wheel and an electric generator to fulfil the speed limit protection of a wind turbine generator.In addition,the authors have designed two sets of 300 W/26 V wind turbine generator,of which the wind wheels and generators have different matching characteristics.To enable them to share an identical base for comparison,electric generators of the same model were used.Through tests,measured were the mechanical output characteristics of the wind wheels,power characteristics of the generators and power output of the whole machine at different output voltages.The test results show that when the wind speed is below 12 m/s,the two wind turbine generators have a basically same power output.When the wind speed is over 12 m/s,one of the two wind turbine generators will increase its power output continuously with an increase of the wind speed,while another will no longer increase its power output with a wind speed increase,but even slightly decrease its power output,similar to the characteristics of a large-sized wind turbine generator.%小型风力发电机面临的最大难题是其可靠性问题,即大风时的限速保护问题.从能量守恒的角度分析了利用风轮与发电机的功率匹配特性实现风力发电机限速保护的可行性.另外,设计了2台风轮与发电机具有不同匹配特性的300 W/26 V风力发电机,为了使其具有可比性,使用了同样型号的发电机.通过实验测试了风轮的机械输出特性、发电机在输出电压不同时的功率特性和整机的功率输出,实验结果表明,风速12 m/s以下时2台风力机输出功率基本相同,风速12 m/s以上时其中1台随着风速的增
Jokinen, T.; Arkkio, A. [Helsinki University of Technology Laboratory of Electromechanics, Otaniemi (Finland)
1997-12-31
The paper deals with various types of highspeed electric motors, and their limiting powers. Standard machines with laminated rotors can be utilised if the speed is moderate. The solid rotor construction makes it possible to reach higher power and speed levels than those of laminated rotors. The development work on high-speed motors done at Helsinki University of Technology is presented, too. (orig.) 12 refs.
赵凤霞; 王正平; 宋学立; 朱景伟; 孙卉卉; 高相彬; 王海涛
2014-01-01
The heavy metal maximum residue limit standard of agricultural products between China and EU was compared to protect health of consumers and meet the demand of export trade development of agricultural products in China and main hazard of Pb,Cd,Hg,Sn,As,Cr and Ni to human body was discussed in the paper.The Pb MRLs of most agricultural products such as cereal,fruits and vegetables in China is no difference with in EU but the Pb MRLs of most agricultural products such as poultry & meat, aquatic animals and dairy products in China is higher than EU.The Cd MRLs of cereal,beans,fruits, vegetables,livestock liver and kidney is no difference with EU but the Cd MRLs of poultry & meat and aquatic products in China is higher than EU.The Hg MRLs of aquatic products is in accord with EU basically and the Hg content in cereal,vegetables,meats,dairy products,eggs and edible mushrooms is regulated in detail.The Sn MRLs of beverages in China is a little more than EU.Total As and inorganic As content in most agricultural products was regulated in GB2762 - 2012.The Ni MRLs of grease and grease products such as hydrogenated vegetable oil and products containing hydrogenated vegetable oil is 1.0 mg/kg.The suggestions to reduce heavy metal content in agricultural products is proposed according to the current status of high heavy metal content in some agricultural products in China compared with developed countries.%为了保护我国消费者的健康，满足农产品出口贸易发展的要求，通过收集整理，简述了 Pb、Cd、Hg、锡（Sn）、As、Cr 和镍（Ni）等几种重金属对人体的主要危害，并对这几种重金属在我国和欧盟主要农产品中的限量标准进行了详细的对比分析。结果表明：Pb，我国谷物、水果和蔬菜等大部分农产品中的限量标准与欧盟一致，禽畜肉类、水产动物类和乳品类等部分农产品中限量标准高于欧盟；Cd，我国的谷物、豆类、水果、蔬菜、禽畜肝脏
Dithering Digital Ripple Correlation Control for Photovoltaic Maximum Power Point Tracking
Barth, C; Pilawa-Podgurski, RCN
2015-08-01
This study demonstrates a new method for rapid and precise maximum power point tracking in photovoltaic (PV) applications using dithered PWM control. Constraints imposed by efficiency, cost, and component size limit the available PWM resolution of a power converter, and may in turn limit the MPP tracking efficiency of the PV system. In these scenarios, PWM dithering can be used to improve average PWM resolution. In this study, we present a control technique that uses ripple correlation control (RCC) on the dithering ripple, thereby achieving simultaneous fast tracking speed and high tracking accuracy. Moreover, the proposed method solves some of the practical challenges that have to date limited the effectiveness of RCC in solar PV applications. We present a theoretical derivation of the principles behind dithering digital ripple correlation control, as well as experimental results that show excellent tracking speed and accuracy with basic hardware requirements.
Maximum likely scale estimation
Loog, Marco; Pedersen, Kim Steenstrup; Markussen, Bo
2005-01-01
A maximum likelihood local scale estimation principle is presented. An actual implementation of the estimation principle uses second order moments of multiple measurements at a fixed location in the image. These measurements consist of Gaussian derivatives possibly taken at several scales and/or ...
受结构限制的运输类飞机最小离地速度试飞技术%Flight test technology of minimum unstick speed for geometry limited airplanes
张建; 屈飞舟; 刘静
2012-01-01
以ARJ21-700飞机最小离地速度试飞为背景,结合民用航空规章相关适航条款要求,研究了受结构限制的运输类飞机最小离地速度的试飞技术和数据处理技术,积累了丰富的最小离地速度试飞经验.该项研究为国内其它运输类飞机的最小离地速度试飞和制定我国自己的民机审定试飞指南具有重要意义.%On the basis of ARJ21 -700 minimum unstick speed flight testing, this paper analysed the flight test technique and data processing method of Vmu test for geometry limited airplanes. The technique and method can be used for minimum unstick speed flight test of other transport airplanes.
Hydroplaning by ducklings: overcoming limitations to swimming at the water surface
Aigeldinger; Fish
1995-01-01
Rapid escape behavior by mallard (Anas platyrhynchos) ducklings is restricted to burst swimming at the water surface. Maximum speed may be limited because of the pattern of waves created as the duckling's body moves through the water (hull speed). Burst speeds for 9-day-old ducklings were compared with predicted hull speeds, based on the waterline length of ducklings either resting in water or actively swimming. Kinematic analysis of video tapes showed a mean maximum burst speed of 1.73 m s-1, which was four times greater than the predicted hull speed. At burst velocities, stroke frequency was 1.9 times higher than the stroke frequency measured during steady low-speed paddling. Transition to burst speeds from steady paddling occurred near predicted hull speed. The paddling motions of the webbed feet were used to generate both thrust and lift. By using lift to raise the body above the water surface, the influence of waves in restricting maximum swimming speed is negated. The duckling's body becomes a planing type of hull and skims on the water surface.
Jesús Peláez Vara
2013-07-01
Full Text Available The aim of this study was to propose and evaluate a very small wind turbine (VSWT that competes with commercial grid-connected VSWTs in terms of simplicity, robustness and price. Its main components are a squirrel-cage induction generator (SCIG driven by a frequency converter. The system has a direct-drive shaft, and may be constructed with commercial equipment. Simulation of the wind turbine effect is done with a motor. A control program regulates the variable-speed of rotation through three operational modes: (i to drive the turbine to its optimum operation point; (ii to limit its maximum rotational speed; and (iii to limit the maximum power it generates. Two tests were performed, in order to evaluate the dynamic response of this system under variable wind speeds. The tests demonstrate that the system operates at the optimum operational point of the turbine, and within the set limits of maximum rotational speed and maximum generated power. The drop in performance in relation to its nominal value is about 75%, when operating at 50% of the nominal power. In summary, this VSWT with its proposed control program is feasible and reliable for operating direct-shaft grid-connected VSWTs.
Intelligent speed adaptation: Preliminary results of on-road study in Penang, Malaysia
S.M.R. Ghadiri
2013-03-01
Full Text Available The first field experiment with intelligent speed adaptation (ISA in Malaysia was held in December 2010 in the State of Penang. Eleven private cars were instrumented with an advisory system. The system used in the present study included a vocal warning message and a visual text message that is activated when the driver attempts to exceed the speed limit. When the driver decreases the speed, the warning stops; otherwise it is continuously repeated. The test drivers drove the vehicles for three months with the installed system, and the speed was continuously logged in all vehicles. The warning was however only activated in the second month of the three month period. The present study aimed to evaluate the effects of an advisory ISA on driving speed, traffic safety, and drivers' attitude, behavior, and acceptance of the system. To examine these effects, both the survey and the logged speed data were analyzed and explored. The results show a significant reduction in the mean, maximum and 85th percentile speed due to the use of the system. However, there was no long-lasting effect on the speed when the system was deactivated. In the post-trial survey, drivers declared that the system helped them well in following the speed limits and that it assisted them in driving more comfortably. Furthermore, the warning method was more accepted compared to a supportive system, such as active accelerator pedal (AAP. After the trial, most drivers were willing to keep an ISA system.
Maximum information photoelectron metrology
Hockett, P; Wollenhaupt, M; Baumert, T
2015-01-01
Photoelectron interferograms, manifested in photoelectron angular distributions (PADs), are a high-information, coherent observable. In order to obtain the maximum information from angle-resolved photoionization experiments it is desirable to record the full, 3D, photoelectron momentum distribution. Here we apply tomographic reconstruction techniques to obtain such 3D distributions from multiphoton ionization of potassium atoms, and fully analyse the energy and angular content of the 3D data. The PADs obtained as a function of energy indicate good agreement with previous 2D data and detailed analysis [Hockett et. al., Phys. Rev. Lett. 112, 223001 (2014)] over the main spectral features, but also indicate unexpected symmetry-breaking in certain regions of momentum space, thus revealing additional continuum interferences which cannot otherwise be observed. These observations reflect the presence of additional ionization pathways and, most generally, illustrate the power of maximum information measurements of th...
De Pauw, Ellen; Daniels, Stijn; Brijs, Tom; Hermans, Elke; Wets, Geert
2014-12-01
The present study evaluates the speed effects of fixed speed cameras on motorways. Two locations with speed cameras were extensively examined in a quasi-experiment: (1) a two-lane motorway and (2) a three-lane motorway, each with a posted speed limit of 120 km/h and sited in Flanders, Belgium. The effect is analysed through a before-and-after comparison of travel speeds. General time trends and fluctuations were controlled through the analysis of the speeds at comparison locations. At each of the two roads, data were gathered at five measurement points from 3 km upstream to 3.8 km downstream of the camera. Three outcomes were analysed: (1) average speed, (2) the odds of drivers exceeding the speed limit and (3) the odds of drivers exceeding the speed limit by more than 10%. Speeds decreased on average by 6.4 km/h at the camera locations. Both the odds of drivers exceeding the speed limit (-80%) and the odds of drivers exceeding the speed limit by more than 10% (-86%) decreased considerably. However, before and beyond the cameras the speeds hardly, if at all, reduced. Moreover, the analyses of the speed profiles before and beyond the cameras show that drivers do slow down quite abruptly before the camera and speed up again after passing the camera. It is concluded that a V-profile is found in the spatial speed distribution for both locations.
Maximum permissible voltage of YBCO coated conductors
Wen, J.; Lin, B.; Sheng, J.; Xu, J.; Jin, Z. [Department of Electrical Engineering, Shanghai Jiao Tong University, Shanghai (China); Hong, Z., E-mail: zhiyong.hong@sjtu.edu.cn [Department of Electrical Engineering, Shanghai Jiao Tong University, Shanghai (China); Wang, D.; Zhou, H.; Shen, X.; Shen, C. [Qingpu Power Supply Company, State Grid Shanghai Municipal Electric Power Company, Shanghai (China)
2014-06-15
Highlights: • We examine three kinds of tapes’ maximum permissible voltage. • We examine the relationship between quenching duration and maximum permissible voltage. • Continuous I{sub c} degradations under repetitive quenching where tapes reaching maximum permissible voltage. • The relationship between maximum permissible voltage and resistance, temperature. - Abstract: Superconducting fault current limiter (SFCL) could reduce short circuit currents in electrical power system. One of the most important thing in developing SFCL is to find out the maximum permissible voltage of each limiting element. The maximum permissible voltage is defined as the maximum voltage per unit length at which the YBCO coated conductors (CC) do not suffer from critical current (I{sub c}) degradation or burnout. In this research, the time of quenching process is changed and voltage is raised until the I{sub c} degradation or burnout happens. YBCO coated conductors test in the experiment are from American superconductor (AMSC) and Shanghai Jiao Tong University (SJTU). Along with the quenching duration increasing, the maximum permissible voltage of CC decreases. When quenching duration is 100 ms, the maximum permissible of SJTU CC, 12 mm AMSC CC and 4 mm AMSC CC are 0.72 V/cm, 0.52 V/cm and 1.2 V/cm respectively. Based on the results of samples, the whole length of CCs used in the design of a SFCL can be determined.
Maximum Likelihood Associative Memories
Gripon, Vincent; Rabbat, Michael
2013-01-01
Associative memories are structures that store data in such a way that it can later be retrieved given only a part of its content -- a sort-of error/erasure-resilience property. They are used in applications ranging from caches and memory management in CPUs to database engines. In this work we study associative memories built on the maximum likelihood principle. We derive minimum residual error rates when the data stored comes from a uniform binary source. Second, we determine the minimum amo...
Maximum likely scale estimation
Loog, Marco; Pedersen, Kim Steenstrup; Markussen, Bo
2005-01-01
A maximum likelihood local scale estimation principle is presented. An actual implementation of the estimation principle uses second order moments of multiple measurements at a fixed location in the image. These measurements consist of Gaussian derivatives possibly taken at several scales and....../or having different derivative orders. Although the principle is applicable to a wide variety of image models, the main focus here is on the Brownian model and its use for scale selection in natural images. Furthermore, in the examples provided, the simplifying assumption is made that the behavior...... of the measurements is completely characterized by all moments up to second order....
2011-02-16
...; Automatic Speed Protection for Design Dive Speed AGENCY: Federal Aviation Administration (FAA), DOT. ACTION... design features include a high speed protection system. These proposed special conditions contain the... Design Features The GVI is equipped with a high speed protection system that limits nose down...
Grip and limb force limits to turning performance in competition horses
Tan, Huiling; Wilson, Alan M.
2011-01-01
Manoeuverability is a key requirement for successful terrestrial locomotion, especially on variable terrain, and is a deciding factor in predator–prey interaction. Compared with straight-line running, bend running requires additional leg force to generate centripetal acceleration. In humans, this results in a reduction in maximum speed during bend running and a published model assuming maximum limb force as a constraint accurately predicts how much a sprinter must slow down on a bend given his maximum straight-line speed. In contrast, greyhounds do not slow down or change stride parameters during bend running, which suggests that their limbs can apply the additional force for this manoeuvre. We collected horizontal speed and angular velocity of heading of horses while they turned in different scenarios during competitive polo and horse racing. The data were used to evaluate the limits of turning performance. During high-speed turns of large radius horizontal speed was lower on the bend, as would be predicted from a model assuming a limb force limit to running speed. During small radius turns the angular velocity of heading decreased with increasing speed in a manner consistent with the coefficient of friction of the hoof–surface interaction setting the limit to centripetal force to avoid slipping. PMID:21147799
Grip and limb force limits to turning performance in competition horses.
Tan, Huiling; Wilson, Alan M
2011-07-22
Manoeuverability is a key requirement for successful terrestrial locomotion, especially on variable terrain, and is a deciding factor in predator-prey interaction. Compared with straight-line running, bend running requires additional leg force to generate centripetal acceleration. In humans, this results in a reduction in maximum speed during bend running and a published model assuming maximum limb force as a constraint accurately predicts how much a sprinter must slow down on a bend given his maximum straight-line speed. In contrast, greyhounds do not slow down or change stride parameters during bend running, which suggests that their limbs can apply the additional force for this manoeuvre. We collected horizontal speed and angular velocity of heading of horses while they turned in different scenarios during competitive polo and horse racing. The data were used to evaluate the limits of turning performance. During high-speed turns of large radius horizontal speed was lower on the bend, as would be predicted from a model assuming a limb force limit to running speed. During small radius turns the angular velocity of heading decreased with increasing speed in a manner consistent with the coefficient of friction of the hoof-surface interaction setting the limit to centripetal force to avoid slipping.
F. TopsÃƒÂ¸e
2001-09-01
Full Text Available Abstract: In its modern formulation, the Maximum Entropy Principle was promoted by E.T. Jaynes, starting in the mid-fifties. The principle dictates that one should look for a distribution, consistent with available information, which maximizes the entropy. However, this principle focuses only on distributions and it appears advantageous to bring information theoretical thinking more prominently into play by also focusing on the "observer" and on coding. This view was brought forward by the second named author in the late seventies and is the view we will follow-up on here. It leads to the consideration of a certain game, the Code Length Game and, via standard game theoretical thinking, to a principle of Game Theoretical Equilibrium. This principle is more basic than the Maximum Entropy Principle in the sense that the search for one type of optimal strategies in the Code Length Game translates directly into the search for distributions with maximum entropy. In the present paper we offer a self-contained and comprehensive treatment of fundamentals of both principles mentioned, based on a study of the Code Length Game. Though new concepts and results are presented, the reading should be instructional and accessible to a rather wide audience, at least if certain mathematical details are left aside at a rst reading. The most frequently studied instance of entropy maximization pertains to the Mean Energy Model which involves a moment constraint related to a given function, here taken to represent "energy". This type of application is very well known from the literature with hundreds of applications pertaining to several different elds and will also here serve as important illustration of the theory. But our approach reaches further, especially regarding the study of continuity properties of the entropy function, and this leads to new results which allow a discussion of models with so-called entropy loss. These results have tempted us to speculate over
Pay as You Speed, ISA with incentive for not speeding: results and interpretation of speed data.
Lahrmann, Harry; Agerholm, Niels; Tradisauskas, Nerius; Berthelsen, Kasper K; Harms, Lisbeth
2012-09-01
To simulate a market introduction of Intelligent Speed Adaptation (ISA) and to study the effect of a Pay as You Speed (PAYS) concept, a field trial with 153 drivers was conducted during 2007-2009. The participants drove under PAYS conditions for a shorter or a longer period. The PAYS concept consisted of informative ISA linked with economic incentive for not speeding, measured through automatic count of penalty points whenever the speed limit was exceeded. The full incentive was set to 30% of a participant's insurance premium. The participants were exposed to different treatments, with and without incentive crossed with informative ISA present or absent. The results showed that ISA is an efficient tool for reducing speeding particularly on rural roads. The analysis of speed data demonstrated that the proportion of distance driven above the speed where the ISA equipment responded (PDA) was a sensitive measure for reflecting the effect of ISA, whereas mean free flow speed and the 85th percentile speed, were less sensitive to ISA effects. The PDA increased a little over time but still remained at a low level; however, when ISA was turned off, the participants' speeding relapsed to the baseline level. Both informative ISA and incentive ISA reduced the PDA, but there was no statistically significant interaction. Informative reduced it more than the incentive.
Regularized maximum correntropy machine
Wang, Jim Jing-Yan
2015-02-12
In this paper we investigate the usage of regularized correntropy framework for learning of classifiers from noisy labels. The class label predictors learned by minimizing transitional loss functions are sensitive to the noisy and outlying labels of training samples, because the transitional loss functions are equally applied to all the samples. To solve this problem, we propose to learn the class label predictors by maximizing the correntropy between the predicted labels and the true labels of the training samples, under the regularized Maximum Correntropy Criteria (MCC) framework. Moreover, we regularize the predictor parameter to control the complexity of the predictor. The learning problem is formulated by an objective function considering the parameter regularization and MCC simultaneously. By optimizing the objective function alternately, we develop a novel predictor learning algorithm. The experiments on two challenging pattern classification tasks show that it significantly outperforms the machines with transitional loss functions.
任沙沙; 庞明宝; 王彦虎; 陈培
2012-01-01
研究基于减法聚类的高速公路混沌系统主线可变速度模糊神经网络控制方法.针对交通系统的不确定性和非线性,提出了通过数据挖掘技术建立高速公路主线混沌控制器知识库的思想,简介了高速公路主线可变速度混沌控制原理,设计了以密度、上游车流量和最大李雅普诺夫指数作为输入,主线速度上限值作为输出的T-S模糊神经网络混沌控制器.采用减法聚类方法确定了控制器结构,包括提取模糊规则、产生控制器初始参数.使用遗传算法对聚类半径进行了优化,并采用模糊神经网络方法对控制器参数进行了优化.仿真结果表明:采用该方法设计的高速公路主线智能混沌控制器,可保持高速公路上的有序运动,从而达到抑制交通堵塞、提高道路通行能力的目的.%The chaos control of freeway mainline was studied by using variable speed limits and fuzzy-neural networks (FNN) based on subtractive clustering. Based on the uncertainty and nonlinearity of traffic system, the thought of establishing the knowledge base of mainline chaos controller for freeway by using data mining technology was proposed. Trie chaos control principle of mainline variable speed limits in freeway was briefly introduced. The T-S FNN chaos controller was designed, where traffic density, upstream traffic volume and maximal Lyapunov exponent were selected as the input variables and the mainline speed upper limit was selected as the output variable of the controller. Subtractive clustering was used to determine the controller structure, including the extracting of fuzzy rules and generating initial parameters. The radius of the clustering centers was optimized by genetic algorithm, and the parameters of the fuzzy controller were optimized by using fuzzy neural network. The simulation result indicates that order motion on freeway can be realized by using the mainline intelligent chaos controller designed by the
Department of Housing and Urban Development — In accordance with 24 CFR Part 92.252, HUD provides maximum HOME rent limits. The maximum HOME rents are the lesser of: The fair market rent for existing housing for...
14 CFR 25.1515 - Landing gear speeds.
2010-01-01
... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Landing gear speeds. 25.1515 Section 25... Limitations § 25.1515 Landing gear speeds. (a) The established landing gear operating speed or speeds, V LO, may not exceed the speed at which it is safe both to extend and to retract the landing gear,...
Equalized near maximum likelihood detector
2012-01-01
This paper presents new detector that is used to mitigate intersymbol interference introduced by bandlimited channels. This detector is named equalized near maximum likelihood detector which combines nonlinear equalizer and near maximum likelihood detector. Simulation results show that the performance of equalized near maximum likelihood detector is better than the performance of nonlinear equalizer but worse than near maximum likelihood detector.
Automatic speed management systems : great safety potential ?
Oei, H.-l.
1992-01-01
An account is given of speed management experiments carried out in The Netherlands on four 2-lane rural roads with a speed limit of 80 km/h. The experiment involved an information campaign, warning signs and a radar camera system. Fixed signs advised a speed of between 60 and 80 km/h and an automati
Cheeseman, Peter; Stutz, John
2005-01-01
A long standing mystery in using Maximum Entropy (MaxEnt) is how to deal with constraints whose values are uncertain. This situation arises when constraint values are estimated from data, because of finite sample sizes. One approach to this problem, advocated by E.T. Jaynes [1], is to ignore this uncertainty, and treat the empirically observed values as exact. We refer to this as the classic MaxEnt approach. Classic MaxEnt gives point probabilities (subject to the given constraints), rather than probability densities. We develop an alternative approach that assumes that the uncertain constraint values are represented by a probability density {e.g: a Gaussian), and this uncertainty yields a MaxEnt posterior probability density. That is, the classic MaxEnt point probabilities are regarded as a multidimensional function of the given constraint values, and uncertainty on these values is transmitted through the MaxEnt function to give uncertainty over the MaXEnt probabilities. We illustrate this approach by explicitly calculating the generalized MaxEnt density for a simple but common case, then show how this can be extended numerically to the general case. This paper expands the generalized MaxEnt concept introduced in a previous paper [3].
Intelligent Speed Adaptation in Company Vehicles
Agerholm, Niels; Tradisauskas, Nerius; Waagepetersen, Rasmus;
2008-01-01
This paper describes an intelligent speed adaptation project for company vehicles. The intelligent speed adaptation function in the project is both information and incentive, which means that the intelligent speed adaptation equipment gives a warning as well as penalty points if the driver...... is speeding. Each month the driver with that monthpsilas fewest points wins an award. The paper presents results concerning speed attitude on the first three of a planned 12 months test period. In all 26 vehicles and 51 drivers from six companies participate in the project. The key result is that speeding...... is reduced from 18.7% to 7.4% on urban roads with a speed limit of 50 km/h while it is reduced from 18.9% to 4.7% on rural roads with a speed limit of 80 km/h....
Clemente, Christofer J; Withers, Philip C; Thompson, Graham
2012-01-01
Studies of locomotor performance often link variation in morphology with ecology. While maximum sprint speed is a commonly used performance variable, the absolute limits for this performance trait are not completely understood. Absolute maximal speed has often been shown to increase linearly with body size, but several comparative studies covering a large range of body sizes suggest that maximal speed does not increase indefinitely with body mass but rather reaches an optimum after which speed declines. Because of the comparative nature of these studies, it is difficult to determine whether this decrease is due to biomechanical constraints on maximal speed or is a consequence of phylogenetic inertia or perhaps relaxed selection for lower maximal speed at large body size. To explore this issue, we have examined intraspecific variations in morphology, maximal sprint speed, and kinematics for the yellow-spotted monitor lizard Varanus panoptes, which varied in body mass from 0.09 to 5.75 kg. We show a curvilinear relationship between body size and absolute maximal sprint speed with an optimal body mass with respect to speed of 1.245 kg. This excludes the phylogenetic inertia hypothesis, because this effect should be absent intraspecifically, while supporting the biomechanical constraints hypothesis. The relaxed selection hypothesis cannot be excluded if there is a size-based behavioral shift intraspecifically, but the biomechanical constraints hypothesis is better supported from kinematic analyses. Kinematic measurements of hind limb movement suggest that the distance moved by the body during the stance phase may limit maximum speed. This limit is thought to be imposed by a decreased ability of the bones and muscles to support body mass for larger lizards.
Maximum Allowable Dynamic Load of Mobile Manipulators with Stability Consideration
Heidary H. R.
2015-09-01
Full Text Available High payload to mass ratio is one of the advantages of mobile robot manipulators. In this paper, a general formula for finding the maximum allowable dynamic load (MADL of wheeled mobile robot is presented. Mobile manipulators operating in field environments will be required to manipulate large loads, and to perform such tasks on uneven terrain, which may cause the system to reach dangerous tip-over instability. Therefore, the method is expanded for finding the MADL of mobile manipulators with stability consideration. Moment-Height Stability (MHS criterion is used as an index for the system stability. Full dynamic model of wheeled mobile base and mounted manipulator is considered with respect to the dynamic of non-holonomic constraint. Then, a method for determination of the maximum allowable loads is described, subject to actuator constraints and by imposing the stability limitation as a new constraint. The actuator torque constraint is applied by using a speed-torque characteristics curve of a typical DC motor. In order to verify the effectiveness of the presented algorithm, several simulation studies considering a two-link planar manipulator, mounted on a mobile base are presented and the results are discussed.
The sun and heliosphere at solar maximum.
Smith, E J; Marsden, R G; Balogh, A; Gloeckler, G; Geiss, J; McComas, D J; McKibben, R B; MacDowall, R J; Lanzerotti, L J; Krupp, N; Krueger, H; Landgraf, M
2003-11-14
Recent Ulysses observations from the Sun's equator to the poles reveal fundamental properties of the three-dimensional heliosphere at the maximum in solar activity. The heliospheric magnetic field originates from a magnetic dipole oriented nearly perpendicular to, instead of nearly parallel to, the Sun's rotation axis. Magnetic fields, solar wind, and energetic charged particles from low-latitude sources reach all latitudes, including the polar caps. The very fast high-latitude wind and polar coronal holes disappear and reappear together. Solar wind speed continues to be inversely correlated with coronal temperature. The cosmic ray flux is reduced symmetrically at all latitudes.
Maximum magnitude earthquakes induced by fluid injection
McGarr, Arthur F.
2014-01-01
Analysis of numerous case histories of earthquake sequences induced by fluid injection at depth reveals that the maximum magnitude appears to be limited according to the total volume of fluid injected. Similarly, the maximum seismic moment seems to have an upper bound proportional to the total volume of injected fluid. Activities involving fluid injection include (1) hydraulic fracturing of shale formations or coal seams to extract gas and oil, (2) disposal of wastewater from these gas and oil activities by injection into deep aquifers, and (3) the development of enhanced geothermal systems by injecting water into hot, low-permeability rock. Of these three operations, wastewater disposal is observed to be associated with the largest earthquakes, with maximum magnitudes sometimes exceeding 5. To estimate the maximum earthquake that could be induced by a given fluid injection project, the rock mass is assumed to be fully saturated, brittle, to respond to injection with a sequence of earthquakes localized to the region weakened by the pore pressure increase of the injection operation and to have a Gutenberg-Richter magnitude distribution with a b value of 1. If these assumptions correctly describe the circumstances of the largest earthquake, then the maximum seismic moment is limited to the volume of injected liquid times the modulus of rigidity. Observations from the available case histories of earthquakes induced by fluid injection are consistent with this bound on seismic moment. In view of the uncertainties in this analysis, however, this should not be regarded as an absolute physical limit.
Maximum magnitude earthquakes induced by fluid injection
McGarr, A.
2014-02-01
Analysis of numerous case histories of earthquake sequences induced by fluid injection at depth reveals that the maximum magnitude appears to be limited according to the total volume of fluid injected. Similarly, the maximum seismic moment seems to have an upper bound proportional to the total volume of injected fluid. Activities involving fluid injection include (1) hydraulic fracturing of shale formations or coal seams to extract gas and oil, (2) disposal of wastewater from these gas and oil activities by injection into deep aquifers, and (3) the development of enhanced geothermal systems by injecting water into hot, low-permeability rock. Of these three operations, wastewater disposal is observed to be associated with the largest earthquakes, with maximum magnitudes sometimes exceeding 5. To estimate the maximum earthquake that could be induced by a given fluid injection project, the rock mass is assumed to be fully saturated, brittle, to respond to injection with a sequence of earthquakes localized to the region weakened by the pore pressure increase of the injection operation and to have a Gutenberg-Richter magnitude distribution with a b value of 1. If these assumptions correctly describe the circumstances of the largest earthquake, then the maximum seismic moment is limited to the volume of injected liquid times the modulus of rigidity. Observations from the available case histories of earthquakes induced by fluid injection are consistent with this bound on seismic moment. In view of the uncertainties in this analysis, however, this should not be regarded as an absolute physical limit.
Improvement of lipase production at different stirring speeds and oxygen levels
F.O.M. Alonso
2005-03-01
Full Text Available Lipase production by a Brazilian wild strain of Yarrowia lipolytica at different stirring speeds and air flow rates was studied. The relationship among lipid consumption, cell growth and lipase production by this microorganism is presented. The most pronounced effect of oxygen on lipase production was determined by stirring speed. Maximum lipase activity was detected in the late stationary phase at 200 rpm and an air flow rate of 1-2 dm³/min (0.8-1.7 vvm when the lipid source had been fully consumed. Higher stirring speeds resulted in mechanical and/or oxidative stress, while lower stirring speeds seemed to limit oxygen levels. An increase in the availability of oxygen at higher air flow rates led to faster lipid uptake and anticipation of enzyme release into the culture medium. The highest lipase production was obtained at 200 rpm and 1 dm³/min (0.8 vvm.
Control of variable speed wind turbines with doubly-fed induction generators
Hansen, A. D.; Soerensen, Poul; Iov, Florin;
2004-01-01
The paper presents an overall control method for variable speed pitch controlled wind turbines with double-feed induction generators (DFIG). Emphasis is on control strategies and algorithms applied at each hierarchical control level of the wind turbine. The objectives of the control system are: 1......) to control the power drawn from the wind turbine in order to track the wind turbine maximum power operation point, 2) to limit the power in case of large wind speeds, and 3) to control the reactive power interchanged between the wind turbine generator and the grid. The present control method is designed...... for normal continuous operations. The strongest feature of the implemented control method is that it allows the turbine to operate with the optimum power efficiency over a wider range of wind speeds. The model of the variable speed, variable pitch wind turbine with doubly-fed induction generator...
Probabilistic maximum-value wind prediction for offshore environments
Staid, Andrea; Pinson, Pierre; Guikema, Seth D.
2015-01-01
, and probabilistic forecasts result in greater value to the end-user. The models outperform traditional baseline forecast methods and achieve low predictive errors on the order of 1–2 m s−1. We show the results of their predictive accuracy for different lead times and different training methodologies....... statistical models to predict the full distribution of the maximum-value wind speeds in a 3 h interval. We take a detailed look at the performance of linear models, generalized additive models and multivariate adaptive regression splines models using meteorological covariates such as gust speed, wind speed......, convective available potential energy, Charnock, mean sea-level pressure and temperature, as given by the European Center for Medium-Range Weather Forecasts forecasts. The models are trained to predict the mean value of maximum wind speed, and the residuals from training the models are used to develop...
Fundamental limitations in antenna resolution by maximum entropy methods
Bevensee, R.M.
1984-08-01
This paper summarizes work done during the past few years on antenna super-resolution of distant radiating sources, both incoherent with and without additive noise and coherent with and without additive noise.
5 CFR 582.402 - Maximum garnishment limitations.
2010-01-01
... Section 582.402 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS... disposable earnings subject to garnishment to enforce any legal debt other than an order for child support or...), shall not exceed 25 percent of the employee-obligor's aggregate disposable earnings for any workweek....
77 FR 37554 - Calculation of Maximum Obligation Limitation
2012-06-22
... Orderly Liquidation Authority (``OLA'') to resolve a large interconnected financial company upon a... on financial stability in the United States and the use of OLA would avoid or mitigate such adverse... of law. \\7\\ Dodd Frank Act, section 202(a)(1)(A)(iii). The OLA in the Dodd-Frank Act is intended as...
76 FR 72645 - Calculation of Maximum Obligation Limitation
2011-11-25
... that fair value measurement is context dependant and the result of numerous variables, including the... fair value of the total consolidated assets of each covered financial company that are available for... of each covered financial company be measured at their ``fair value.'' The Dodd-Frank Act does not...
A high-speed BCI based on code modulation VEP
Bin, Guangyu; Gao, Xiaorong; Wang, Yijun; Li, Yun; Hong, Bo; Gao, Shangkai
2011-04-01
Recently, electroencephalogram-based brain-computer interfaces (BCIs) have attracted much attention in the fields of neural engineering and rehabilitation due to their noninvasiveness. However, the low communication speed of current BCI systems greatly limits their practical application. In this paper, we present a high-speed BCI based on code modulation of visual evoked potentials (c-VEP). Thirty-two target stimuli were modulated by a time-shifted binary pseudorandom sequence. A multichannel identification method based on canonical correlation analysis (CCA) was used for target identification. The online system achieved an average information transfer rate (ITR) of 108 ± 12 bits min-1 on five subjects with a maximum ITR of 123 bits min-1 for a single subject.
Speed Control of Induction Motor by Using Variable Frequency
Drive Pooja Shinde; Rupali Burungale
2014-01-01
The variable speed drive is focused on voltage amplitude control. However, its only control speed in constraint limits. The load on Induction Motor is not constant & vary as per load requirement. so speed must be change as per load. If the supply voltage decreased motor torque also decreases, for maintaining same torque, slip decreases hence speed falls and motor speed is directly proportional to supply frequency, hence to maintain a speed, the supply V/F ratio must be vary ac...
Viability of gait speed test in hospitalized elderly patients
Bruno Prata Martinez
Full Text Available ABSTRACT Objective: The gait speed test (GST is a physical test that can predict falls and aid in the diagnosis of sarcopenia in the elderly. However, to our knowledge, there have been no studies evaluating its reproducibility in hospitalized elderly patients. The objective of this study was to evaluate the safety and reproducibility of the six-meter GST (6GST in hospitalized elderly patients. Methods: This repeated measures study involved hospitalized elderly patients (≥ 60 years of age who underwent the 6GST by the fifth day of hospitalization, were able to walk without assistance, and presented no signs of dyspnea or pain that would prevent them from performing the test. The 6GST was performed three times in sequence, with a rest period between each test, in a level corridor. Gait speed was measured in meters/second. Reproducibility was assessed by comparing the means, intraclass correlation coefficients (ICCs and Bland-Altman plots. Results: We evaluated 110 elderly patients in a total of 330 tests. All participants completed all of the tests. The comparisons between the speeds obtained during the three tests showed high ICCs and a low mean bias (Bland-Altman plots. The correlation and accuracy were greatest when the mean maximum speed was compared with that obtained in the third test (1.26 ± 0.44 m/s vs. 1.22 ± 0.44 m/s; ICC = 0.99; p = 0.001; mean bias = 0.04; and limits of agreement = −0.27 to 0.15. Conclusions: The 6GST was proven to be safe and to have good reproducibility in this sample of hospitalized elderly patients. The third measurement seems to correspond to the maximum speed, since the first two measurements underestimated the actual performance.
14 CFR 23.253 - High speed characteristics.
2010-01-01
... conditions and characteristics likely to cause inadvertent speed increases (including upsets in pitch and... about any axis at any speed up to the maximum speed shown under § 23.251. Any reversal of elevator control force or tendency of the airplane to pitch, roll, or yaw must be mild and readily controllable...
14 CFR 23.73 - Reference landing approach speed.
2010-01-01
... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Reference landing approach speed. 23.73... Reference landing approach speed. (a) For normal, utility, and acrobatic category reciprocating engine-powered airplanes of 6,000 pounds or less maximum weight, the reference landing approach speed, VREF,...
Public acceptance of enforced speed adaptation in the urban area
Katteler, H.A.; Heijden, R.E.C.M. van der
2005-01-01
This paper discusses a way to drastically cope with speeding in the urban area. Pilots with Intelligent Speed Adaptation (ISA) in Europe applied in passenger cars support the perspective of creating an urban environment with a guaranteed maximum speed level for car drivers. Therefore, the
Intelligent speed control and effects on driving behaviour
Horst, A.R.A. van der; Hogema, J.H.
1999-01-01
Supporting the driver in conducting his nowadays demanding task is a promising means to get the maximum out of the road system with respect to both efficiency and safety. With respect to safety, speed management is a main issue. Police enforcement of speeding is one approach, preventing high speeds
Maximum stellar iron core mass
F W Giacobbe
2003-03-01
An analytical method of estimating the mass of a stellar iron core, just prior to core collapse, is described in this paper. The method employed depends, in part, upon an estimate of the true relativistic mass increase experienced by electrons within a highly compressed iron core, just prior to core collapse, and is signiﬁcantly different from a more typical Chandrasekhar mass limit approach. This technique produced a maximum stellar iron core mass value of 2.69 × 1030 kg (1.35 solar masses). This mass value is very near to the typical mass values found for neutron stars in a recent survey of actual neutron star masses. Although slightly lower and higher neutron star masses may also be found, lower mass neutron stars are believed to be formed as a result of enhanced iron core compression due to the weight of non-ferrous matter overlying the iron cores within large stars. And, higher mass neutron stars are likely to be formed as a result of fallback or accretion of additional matter after an initial collapse event involving an iron core having a mass no greater than 2.69 × 1030 kg.
Maximum permissible voltage of YBCO coated conductors
Wen, J.; Lin, B.; Sheng, J.; Xu, J.; Jin, Z.; Hong, Z.; Wang, D.; Zhou, H.; Shen, X.; Shen, C.
2014-06-01
Superconducting fault current limiter (SFCL) could reduce short circuit currents in electrical power system. One of the most important thing in developing SFCL is to find out the maximum permissible voltage of each limiting element. The maximum permissible voltage is defined as the maximum voltage per unit length at which the YBCO coated conductors (CC) do not suffer from critical current (Ic) degradation or burnout. In this research, the time of quenching process is changed and voltage is raised until the Ic degradation or burnout happens. YBCO coated conductors test in the experiment are from American superconductor (AMSC) and Shanghai Jiao Tong University (SJTU). Along with the quenching duration increasing, the maximum permissible voltage of CC decreases. When quenching duration is 100 ms, the maximum permissible of SJTU CC, 12 mm AMSC CC and 4 mm AMSC CC are 0.72 V/cm, 0.52 V/cm and 1.2 V/cm respectively. Based on the results of samples, the whole length of CCs used in the design of a SFCL can be determined.
Measurement of vehicles speed with full waveform lidar
Muzal, Michał; Mierczyk, Zygmunt; Zygmunt, Marek; Wojtanowski, Jacek; Piotrowski, Wiesław
2016-12-01
Measurement of vehicles speed by means of displacement measurement with "time of flight" lidar requires gathering of accurate information about distance to the vehicle in a set time interval. As with any pulsed laser lidar, its maximum range is limited by available incoming signal to noise ratio. That ratio determines not only maximum range, but also accuracy of measurement. For fast and precise measurements of speed of the vehicles their displacement should bee measured with centimeter accuracy. However that demand is hard to reach on long distances and poor quality of the echo signal. Improving accuracy beyond given by a single pulse probing requires emission of several probing pulses. Total displacement error will than fall with the square root of the number of executed measurements. Yet this method will not extend available distance beyond the limit set by threshold detection systems. Acquisition of the full waveform of received signals is a method that allows extension of maximum range through synchronic addition of subsequent waveforms. Doing so improves SNR by a well-known factor of square root of the number of carried additions. Disadvantage of this method is that it requires use of fast analog to digital converters for data acquisition, and simple distance calculation algorithms may not give the adequate accuracy due to relatively long sampling period of reasonable priced ADC's. In this article more advanced algorithms of distance calculations that base on ADC raw data are presented and analyzed. Practical implementation of algorithm in prototype design of laser speed gun is shown along with real life test results.
Bittel, R.; Mancel, J. [Commissariat a l' Energie Atomique, 92 - Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires, departement de la protection sanitaire
1968-10-01
The most important carriers of radioactive contamination of man are the whole of foodstuffs and not only ingested water or inhaled air. That is the reason why, in accordance with the spirit of the recent recommendations of the ICRP, it is proposed to substitute the idea of maximum levels of contamination of water to the MPC. In the case of aquatic food chains (aquatic organisms and irrigated foodstuffs), the knowledge of the ingested quantities and of the concentration factors food/water permit to determinate these maximum levels, or to find out a linear relation between the maximum levels in the case of two primary carriers of contamination (continental and sea waters). The notion of critical food-consumption, critical radioelements and formula of waste disposal are considered in the same way, taking care to attach the greatest possible importance to local situations. (authors) [French] Les vecteurs essentiels de la contamination radioactive de l'homme sont les aliments dans leur ensemble, et non seulement l'eau ingeree ou l'air inhale. C'est pourquoi, en accord avec l'esprit des recentes recommandations de la C.I.P.R., il est propose de substituer aux CMA la notion de niveaux limites de contamination des eaux. Dans le cas des chaines alimentaires aquatiques (organismes aquatiques et aliments irrigues), la connaissance des quantites ingerees et celle des facteurs de concentration aliments/eau permettent de determiner ces niveaux limites dans le cas de deux vecteurs primaires de contamination (eaux continentales et eaux oceaniques). Les notions de regime alimentaire critique, de radioelement critique et de formule de rejets sont envisagees, dans le meme esprit, avec le souci de tenir compte le plus possible des situations locales. (auteurs)
Maximum floodflows in the conterminous United States
Crippen, John R.; Bue, Conrad D.
1977-01-01
Peak floodflows from thousands of observation sites within the conterminous United States were studied to provide a guide for estimating potential maximum floodflows. Data were selected from 883 sites with drainage areas of less than 10,000 square miles (25,900 square kilometers) and were grouped into regional sets. Outstanding floods for each region were plotted on graphs, and envelope curves were computed that offer reasonable limits for estimates of maximum floods. The curves indicate that floods may occur that are two to three times greater than those known for most streams.
Wide-area scanner for high-speed atomic force microscopy
Watanabe, Hiroki; Uchihashi, Takayuki; Kobashi, Toshihide; Shibata, Mikihiro; Nishiyama, Jun; Yasuda, Ryohei; Ando, Toshio
2013-01-01
High-speed atomic force microscopy (HS-AFM) has recently been established. The dynamic processes and structural dynamics of protein molecules in action have been successfully visualized using HS-AFM. However, its maximum scan ranges in the X- and Y-directions have been limited to ∼1 μm and ∼4 μm, respectively, making it infeasible to observe the dynamics of much larger samples, including live cells. Here, we develop a wide-area scanner with a maximum XY scan range of ∼46 × 46 μm2 by magnifyin...
Béguin, A.; Nicolet, C.; Hell, J.; Moreira, C.
2017-04-01
The paper explores the improvement in ancillary services that variable speed technologies can provide for the case of an existing pumped storage power plant of 2x210 MVA which conversion from fixed speed to variable speed is investigated with a focus on the power step performances of the units. First two motor-generator variable speed technologies are introduced, namely the Doubly Fed Induction Machine (DFIM) and the Full Scale Frequency Converter (FSFC). Then a detailed numerical simulation model of the investigated power plant used to simulate power steps response and comprising the waterways, the pump-turbine unit, the motor-generator, the grid connection and the control systems is presented. Hydroelectric system time domain simulations are performed in order to determine the shortest response time achievable, taking into account the constraints from the maximum penstock pressure and from the rotational speed limits. It is shown that the maximum instantaneous power step response up and down depends on the hydro-mechanical characteristics of the pump-turbine unit and of the motor-generator speed limits. As a results, for the investigated test case, the FSFC solution offer the best power step response performances.
14 CFR 25.1517 - Rough air speed, VRA.
2010-01-01
... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Rough air speed, VRA. 25.1517 Section 25... Limitations § 25.1517 Rough air speed, VRA. A rough air speed, VRA, for use as the recommended turbulence... specified in § 25.335(d); and (3) Is sufficiently less than VMO to ensure that likely speed variation...
Ali, Ahmed MA
2016-01-01
This book covers high speed data converters from the perspective of a leading high speed ADC designer and architect, with a strong emphasis on high speed Nyquist A/D converters. For our purposes, the term 'high speed' is defined as sampling rates that are greater than 10 MS/s.
The maximum rate of mammal evolution
Evans, Alistair R.; Jones, David; Boyer, Alison G.; Brown, James H.; Costa, Daniel P.; Ernest, S. K. Morgan; Fitzgerald, Erich M. G.; Fortelius, Mikael; Gittleman, John L.; Hamilton, Marcus J.; Harding, Larisa E.; Lintulaakso, Kari; Lyons, S. Kathleen; Okie, Jordan G.; Saarinen, Juha J.; Sibly, Richard M.; Smith, Felisa A.; Stephens, Patrick R.; Theodor, Jessica M.; Uhen, Mark D.
2012-03-01
How fast can a mammal evolve from the size of a mouse to the size of an elephant? Achieving such a large transformation calls for major biological reorganization. Thus, the speed at which this occurs has important implications for extensive faunal changes, including adaptive radiations and recovery from mass extinctions. To quantify the pace of large-scale evolution we developed a metric, clade maximum rate, which represents the maximum evolutionary rate of a trait within a clade. We applied this metric to body mass evolution in mammals over the last 70 million years, during which multiple large evolutionary transitions occurred in oceans and on continents and islands. Our computations suggest that it took a minimum of 1.6, 5.1, and 10 million generations for terrestrial mammal mass to increase 100-, and 1,000-, and 5,000-fold, respectively. Values for whales were down to half the length (i.e., 1.1, 3, and 5 million generations), perhaps due to the reduced mechanical constraints of living in an aquatic environment. When differences in generation time are considered, we find an exponential increase in maximum mammal body mass during the 35 million years following the Cretaceous-Paleogene (K-Pg) extinction event. Our results also indicate a basic asymmetry in macroevolution: very large decreases (such as extreme insular dwarfism) can happen at more than 10 times the rate of increases. Our findings allow more rigorous comparisons of microevolutionary and macroevolutionary patterns and processes.
The maximum rate of mammal evolution
Evans, Alistair R.; Jones, David; Boyer, Alison G.; Brown, James H.; Costa, Daniel P.; Ernest, S. K. Morgan; Fitzgerald, Erich M. G.; Fortelius, Mikael; Gittleman, John L.; Hamilton, Marcus J.; Harding, Larisa E.; Lintulaakso, Kari; Lyons, S. Kathleen; Okie, Jordan G.; Saarinen, Juha J.; Sibly, Richard M.; Smith, Felisa A.; Stephens, Patrick R.; Theodor, Jessica M.; Uhen, Mark D.
2012-01-01
How fast can a mammal evolve from the size of a mouse to the size of an elephant? Achieving such a large transformation calls for major biological reorganization. Thus, the speed at which this occurs has important implications for extensive faunal changes, including adaptive radiations and recovery from mass extinctions. To quantify the pace of large-scale evolution we developed a metric, clade maximum rate, which represents the maximum evolutionary rate of a trait within a clade. We applied this metric to body mass evolution in mammals over the last 70 million years, during which multiple large evolutionary transitions occurred in oceans and on continents and islands. Our computations suggest that it took a minimum of 1.6, 5.1, and 10 million generations for terrestrial mammal mass to increase 100-, and 1,000-, and 5,000-fold, respectively. Values for whales were down to half the length (i.e., 1.1, 3, and 5 million generations), perhaps due to the reduced mechanical constraints of living in an aquatic environment. When differences in generation time are considered, we find an exponential increase in maximum mammal body mass during the 35 million years following the Cretaceous–Paleogene (K–Pg) extinction event. Our results also indicate a basic asymmetry in macroevolution: very large decreases (such as extreme insular dwarfism) can happen at more than 10 times the rate of increases. Our findings allow more rigorous comparisons of microevolutionary and macroevolutionary patterns and processes. PMID:22308461
The maximum rate of mammal evolution.
Evans, Alistair R; Jones, David; Boyer, Alison G; Brown, James H; Costa, Daniel P; Ernest, S K Morgan; Fitzgerald, Erich M G; Fortelius, Mikael; Gittleman, John L; Hamilton, Marcus J; Harding, Larisa E; Lintulaakso, Kari; Lyons, S Kathleen; Okie, Jordan G; Saarinen, Juha J; Sibly, Richard M; Smith, Felisa A; Stephens, Patrick R; Theodor, Jessica M; Uhen, Mark D
2012-03-13
How fast can a mammal evolve from the size of a mouse to the size of an elephant? Achieving such a large transformation calls for major biological reorganization. Thus, the speed at which this occurs has important implications for extensive faunal changes, including adaptive radiations and recovery from mass extinctions. To quantify the pace of large-scale evolution we developed a metric, clade maximum rate, which represents the maximum evolutionary rate of a trait within a clade. We applied this metric to body mass evolution in mammals over the last 70 million years, during which multiple large evolutionary transitions occurred in oceans and on continents and islands. Our computations suggest that it took a minimum of 1.6, 5.1, and 10 million generations for terrestrial mammal mass to increase 100-, and 1,000-, and 5,000-fold, respectively. Values for whales were down to half the length (i.e., 1.1, 3, and 5 million generations), perhaps due to the reduced mechanical constraints of living in an aquatic environment. When differences in generation time are considered, we find an exponential increase in maximum mammal body mass during the 35 million years following the Cretaceous-Paleogene (K-Pg) extinction event. Our results also indicate a basic asymmetry in macroevolution: very large decreases (such as extreme insular dwarfism) can happen at more than 10 times the rate of increases. Our findings allow more rigorous comparisons of microevolutionary and macroevolutionary patterns and processes.
Glendon, A Ian; Walker, Britta L
2013-08-01
The study investigated the effects of anti-speeding messages based on protection motivation theory (PMT) components: severity, vulnerability, rewards, self-efficacy, response efficacy, and response cost, on reported speeding intentions. Eighty-three participants aged 18-25 years holding a current Australian driver's license completed a questionnaire measuring their reported typical and recent speeding behaviors. Comparisons were made between 18 anti-speeding messages used on Australian roads and 18 new anti-speeding messages developed from the PMT model. Participants reported their reactions to the 36 messages on the perceived effectiveness of the message for themselves and for the general population of drivers, and also the likelihood of themselves and other drivers driving within the speed limit after viewing each message. Overall the PMT model-derived anti-speeding messages were better than jurisdiction-use anti-speeding messages in influencing participants' reported intention to drive within the speed limit. Severity and vulnerability were the most effective PMT components for developing anti-speeding messages. Male participants reported significantly lower intention to drive within the speed limit than did female participants. However, males reported significantly higher intention to drive within the speed limit for PMT-derived messages compared with jurisdiction-based messages. Third-person effects were that males reported anti-speeding messages to be more effective for the general driving population than for themselves. Females reported the opposite effect - that all messages would be more effective for themselves than for the general driving population. Findings provided support for using a sound conceptual basis as an effective foundation for anti-speeding message development as well as for evaluating proposed anti-speeding messages on the target driver population. Copyright © 2013 Elsevier Ltd. All rights reserved.
2007-01-01
In view of the significant number of speeding incidents that have been reported, CERN will shortly start to carry out speed checks on the site. The radar used for this purpose will show drivers the speed measured. The disciplinary measures taken against those exceeding the authorised limit (generally 50 k.p.h.) will include a ban from driving on the site for a minimum of one month. Maximilian Metzger Secretary-General
Speeding chemical reactions by focusing
Lacasta, A M; Sancho, J M; Lindenberg, K
2012-01-01
We present numerical results for a chemical reaction of colloidal particles which are transported by a laminar fluid and are focused by periodic obstacles in such a way that the two components are well mixed and consequently the chemical reaction is speeded up. The roles of the various system parameters (diffusion coefficients, reaction rate, obstacles sizes) are studied. We show that focusing speeds up the reaction from the diffusion limited rate (t to the power -1/2) to very close to the perfect mixing rate, (t to the power -1).
High-speed photonics interconnects
Chrostowski, Lukas
2013-01-01
Dramatic increases in processing power have rapidly scaled on-chip aggregate bandwidths into the Tb/s range. This necessitates a corresponding increase in the amount of data communicated between chips, so as not to limit overall system performance. To meet the increasing demand for interchip communication bandwidth, researchers are investigating the use of high-speed optical interconnect architectures. Unlike their electrical counterparts, optical interconnects offer high bandwidth and negligible frequency-dependent loss, making possible per-channel data rates of more than 10 Gb/s. High-Speed
Quality, precision and accuracy of the maximum No. 40 anemometer
Obermeir, J. [Otech Engineering, Davis, CA (United States); Blittersdorf, D. [NRG Systems Inc., Hinesburg, VT (United States)
1996-12-31
This paper synthesizes available calibration data for the Maximum No. 40 anemometer. Despite its long history in the wind industry, controversy surrounds the choice of transfer function for this anemometer. Many users are unaware that recent changes in default transfer functions in data loggers are producing output wind speed differences as large as 7.6%. Comparison of two calibration methods used for large samples of Maximum No. 40 anemometers shows a consistent difference of 4.6% in output speeds. This difference is significantly larger than estimated uncertainty levels. Testing, initially performed to investigate related issues, reveals that Gill and Maximum cup anemometers change their calibration transfer functions significantly when calibrated in the open atmosphere compared with calibration in a laminar wind tunnel. This indicates that atmospheric turbulence changes the calibration transfer function of cup anemometers. These results call into question the suitability of standard wind tunnel calibration testing for cup anemometers. 6 refs., 10 figs., 4 tabs.
Maximum entropy analysis of cosmic ray composition
Nosek, Dalibor; Vícha, Jakub; Trávníček, Petr; Nosková, Jana
2016-01-01
We focus on the primary composition of cosmic rays with the highest energies that cause extensive air showers in the Earth's atmosphere. A way of examining the two lowest order moments of the sample distribution of the depth of shower maximum is presented. The aim is to show that useful information about the composition of the primary beam can be inferred with limited knowledge we have about processes underlying these observations. In order to describe how the moments of the depth of shower maximum depend on the type of primary particles and their energies, we utilize a superposition model. Using the principle of maximum entropy, we are able to determine what trends in the primary composition are consistent with the input data, while relying on a limited amount of information from shower physics. Some capabilities and limitations of the proposed method are discussed. In order to achieve a realistic description of the primary mass composition, we pay special attention to the choice of the parameters of the sup...
Causality and the speed of sound
Ellis, G; MacCallum, M; Callum, Malcolm Mac; Ellis, George; Maartens, Roy
2007-01-01
A usual causal requirement on a viable theory of matter is that the speed of sound be at most the speed of light. In view of various recent papers querying this limit, the question is revisited here. We point to various issues confronting theories that violate the usual constraint.
Small high-speed dynamic target at close range laser active imaging system
Yao, Jun; Wang, Du-yue; Zhang, Zheng; Zhang, Yue; Dai, Qin
2016-11-01
In the shooting range measuring, all-weather, high speed, unattended, the new concepts such as the remote control is gradually applied. In this paper, a new type of low cost range measurement system, using FPGA + MCU as electronic control system of laser active illumination and high-speed CMOS camera, data to the rear zone by using optical fiber communications, transmission and realizes the remote control of unmanned, due to the low cost of front-end equipment, can be used as consumables replacement at any time, combined with distributed layout principle, can maximum limit close to the measured with mutilate ability goal, thus to achieve the goal of small high-speed dynamic imaging from close range.
Comparison of High Speed Congestion Control Protocols
Jawhar Ben Abed
2012-10-01
Full Text Available Congestion control limits the quantity of information input at a rate less important than that of thetransmission one to ensure good performance as well as protect against overload and blocking of thenetwork. Researchers have done a great deal of work on improving congestion control protocols,especially on high speed networks.In this paper, we will be studying the congestion control alongside low and high speed congestion controlprotocols. We will be also simulating, evaluating, and comparing eight of high speed congestion controlprotocols : Bic TCP, Cubic TCP, Hamilton TCP, HighSpeed TCP, Illinois TCP, Scalable TCP,Compound TCP and YeAH TCP, with multiple flows.
14 CFR 25.1583 - Operating limitations.
2010-01-01
... or pilot training. (2) If an airspeed limitation is based upon compressibility effects, a statement... engine powers. (5) The landing gear operating speed or speeds, and a statement explaining the speeds as defined in § 25.1515(a). (6) The landing gear extended speed V LE, if greater than V LO, and a...
Minimizing Maximum Response Time and Delay Factor in Broadcast Scheduling
Chekuri, Chandra; Moseley, Benjamin
2009-01-01
We consider online algorithms for pull-based broadcast scheduling. In this setting there are n pages of information at a server and requests for pages arrive online. When the server serves (broadcasts) a page p, all outstanding requests for that page are satisfied. We study two related metrics, namely maximum response time (waiting time) and maximum delay-factor and their weighted versions. We obtain the following results in the worst-case online competitive model. - We show that FIFO (first-in first-out) is 2-competitive even when the page sizes are different. Previously this was known only for unit-sized pages [10] via a delicate argument. Our proof differs from [10] and is perhaps more intuitive. - We give an online algorithm for maximum delay-factor that is O(1/eps^2)-competitive with (1+\\eps)-speed for unit-sized pages and with (2+\\eps)-speed for different sized pages. This improves on the algorithm in [12] which required (2+\\eps)-speed and (4+\\eps)-speed respectively. In addition we show that the algori...
Maximum margin Bayesian network classifiers.
Pernkopf, Franz; Wohlmayr, Michael; Tschiatschek, Sebastian
2012-03-01
We present a maximum margin parameter learning algorithm for Bayesian network classifiers using a conjugate gradient (CG) method for optimization. In contrast to previous approaches, we maintain the normalization constraints on the parameters of the Bayesian network during optimization, i.e., the probabilistic interpretation of the model is not lost. This enables us to handle missing features in discriminatively optimized Bayesian networks. In experiments, we compare the classification performance of maximum margin parameter learning to conditional likelihood and maximum likelihood learning approaches. Discriminative parameter learning significantly outperforms generative maximum likelihood estimation for naive Bayes and tree augmented naive Bayes structures on all considered data sets. Furthermore, maximizing the margin dominates the conditional likelihood approach in terms of classification performance in most cases. We provide results for a recently proposed maximum margin optimization approach based on convex relaxation. While the classification results are highly similar, our CG-based optimization is computationally up to orders of magnitude faster. Margin-optimized Bayesian network classifiers achieve classification performance comparable to support vector machines (SVMs) using fewer parameters. Moreover, we show that unanticipated missing feature values during classification can be easily processed by discriminatively optimized Bayesian network classifiers, a case where discriminative classifiers usually require mechanisms to complete unknown feature values in the data first.
Maximum Entropy in Drug Discovery
Chih-Yuan Tseng
2014-07-01
Full Text Available Drug discovery applies multidisciplinary approaches either experimentally, computationally or both ways to identify lead compounds to treat various diseases. While conventional approaches have yielded many US Food and Drug Administration (FDA-approved drugs, researchers continue investigating and designing better approaches to increase the success rate in the discovery process. In this article, we provide an overview of the current strategies and point out where and how the method of maximum entropy has been introduced in this area. The maximum entropy principle has its root in thermodynamics, yet since Jaynes’ pioneering work in the 1950s, the maximum entropy principle has not only been used as a physics law, but also as a reasoning tool that allows us to process information in hand with the least bias. Its applicability in various disciplines has been abundantly demonstrated. We give several examples of applications of maximum entropy in different stages of drug discovery. Finally, we discuss a promising new direction in drug discovery that is likely to hinge on the ways of utilizing maximum entropy.
Middleton, Addie; Fulk, George D; Herter, Troy M; Beets, Michael W; Donley, Jonathan; Fritz, Stacy L
2016-07-01
To determine the degree to which self-selected walking speed (SSWS), maximal walking speed (MWS), and walking speed reserve (WSR) are associated with fall status among community-dwelling older adults. WS and 1-year falls history data were collected on 217 community-dwelling older adults (median age = 82, range 65-93 years) at a local outpatient PT clinic and local retirement communities and senior centers. WSR was calculated as a difference (WSRdiff = MWS - SSWS) and ratio (WSRratio = MWS/SSWS). SSWS (P risk assessment. Combining SSWS and MWS to calculate an individual's WSR does not provide additional insight into fall status in this population. Complete the self-assessment activity and evaluation online at http://www.physiatry.org/JournalCME CME OBJECTIVES:: Upon completion of this article, the reader should be able to: (1) Describe the different methods for calculating walking speed reserve and discuss the potential of the metric as an outcome measure; (2) Explain the degree to which self-selected walking speed, maximal walking speed, and walking speed reserve are associated with fall status among community-dwelling older adults; and (3) Discuss potential limitations to using walking speed reserve to identify fall status in populations without mobility restrictions. Advanced : The Association of Academic Physiatrists is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians. The Association of Academic Physiatrists designates this activity for a maximum of 1.5 AMA PRA Category 1 Credit(s). Physicians should only claim credit commensurate with the extent of their participation in the activity.
Optimization of agitation and aeration conditions for maximum virginiamycin production.
Shioya, S; Morikawa, M; Kajihara, Y; Shimizu, H
1999-02-01
To maximize the productivity of virginiamycin, which is a commercially important antibiotic as an animal feed additive, an empirical approach was employed in the batch culture of Streptomyces virginiae. Here, the effects of dissolved oxygen (DO) concentration and agitation speed on the maximum cell concentration at the production phase, as well as on the productivity of virginiamycin, were investigated. To maintain the DO concentration in the fermentor at a certain level, either the agitation speed or the inlet oxygen concentration of the supply gas was manipulated. It was found that increasing the agitation speed had a positive effect on the antibiotic productivity independent of the DO concentration. The optimum DO concentration, agitation speed and addition of an autoregulator, virginiae butanolide C (VB-C), were determined to maximize virginiamycin productivity. The optimal strategy was to start the cultivation at 450 rpm and to continue until the DO concentration reached 80%. After reaching 80%, the DO concentration was maintained at this level by changing the agitation speed, up to a maximum of 800 rpm. The addition of an optimal amount of the autoregulator VB-C in an experiment resulted in the maximal production of virginiamycin M (399 mg/l), which was about 1.8-fold those obtained previously.
Effect of phase advance on the brushless dc motor torque speed respond
Mohd, M. S.; Karsiti, M. N.; Mohd, M. S.
2015-12-01
Brushless direct current (BLDC) motor is widely used in small and medium sized electric vehicles as it exhibit highest specific power and thermal efficiency as compared to the induction motor. Permanent magnets BLDC rotor create a constant magnetic flux, which limit the motor top speed. As the back electromotive force (EMF) voltage increases proportionally with motor rotational speed and it approaches the amplitude of the input voltage, the phase current amplitude will reach zero. By advancing the phase current, it is possible to extend the maximum speed of the BLDC motor beyond the rated top speed. This will allow smaller BLDC motor to be used in small electric vehicles (EV) and in larger applications will allow the use of BLDC motor without the use of multispeed transmission unit for high speed operation. However, increasing the speed of BLDC will affect the torque speed response. The torque output will decrease as speed increases. Adjusting the phase angle will affect the speed of the motor as each coil is energized earlier than the corresponding rise in the back emf of the coil. This paper discusses the phase advance strategy of Brushless DC motor by phase angle manipulation approaches using external hall sensors. Tests have been performed at different phase advance angles in advance and retard positions for different voltage levels applied. The objective is to create the external hall sensor system to commutate the BLDC motor, to establish the phase advance of the BLDC by varying the phase angle through external hall sensor manipulation, observe the respond of the motor while applying the phase advance by hall sensor adjustment.
Performance of twist-coupled blades on variable speed rotors
Lobitz, D.W.; Veers, P.S.; Laino, D.J.
1999-12-07
The load mitigation and energy capture characteristics of twist-coupled HAWT blades that are mounted on a variable speed rotor are investigated in this paper. These blades are designed to twist toward feather as they bend with pretwist set to achieve a desirable twist distribution at rated power. For this investigation, the ADAMS-WT software has been modified to include blade models with bending-twist coupling. Using twist-coupled and uncoupled models, the ADAMS software is exercised for steady wind environments to generate C{sub p} curves at a number of operating speeds to compare the efficiencies of the two models. The ADAMS software is also used to generate the response of a twist-coupled variable speed rotor to a spectrum of stochastic wind time series. This spectrum contains time series with two mean wind speeds at two turbulence levels. Power control is achieved by imposing a reactive torque on the low speed shaft proportional to the RPM squared with the coefficient specified so that the rotor operates at peak efficiency in the linear aerodynamic range, and by limiting the maximum RPM to take advantage of the stall controlled nature of the rotor. Fatigue calculations are done for the generated load histories using a range of material exponents that represent materials from welded steel to aluminum to composites, and results are compared with the damage computed for the rotor without twist-coupling. Results indicate that significant reductions in damage are achieved across the spectrum of applied wind loading without any degradation in power production.
Power of a Finite Speed Carnot Engine
Agrawal, D. C.; Menon, V. J.
2009-01-01
A model of an endoreversible Carnot engine is considered where the piston moves with a constant speed "u." Expressions for the cycle time [tau] for the four branches, as well as output power, P[subscript W], are derived and the optimized root for maximum power is obtained in closed form. Our results are discussed in terms of the isothermal…
5 CFR 838.711 - Maximum former spouse survivor annuity.
2010-01-01
... 5 Administrative Personnel 2 2010-01-01 2010-01-01 false Maximum former spouse survivor annuity... Orders Awarding Former Spouse Survivor Annuities Limitations on Survivor Annuities § 838.711 Maximum former spouse survivor annuity. (a) Under CSRS, payments under a court order may not exceed the...
Meglio, Olimpia; King, David R.; Risberg, Annette
2017-01-01
The advantage of speed is often invoked by academics and practitioners as an essential condition during post-acquisition integration, frequently without consideration of the impact earlier decisions have on acquisition speed. In this article, we examine the role speed plays in acquisitions across...... the acquisition process using research organized around characteristics that display complexity with respect to acquisition speed. We incorporate existing research with a process perspective of acquisitions in order to present trade-offs, and consider the influence of both stakeholders and the pre......-deal-completion context on acquisition speed, as well as the organization’s capabilities to facilitating that speed. Observed trade-offs suggest both that acquisition speed often requires longer planning time before an acquisition and that associated decisions require managerial judgement. A framework for improving...
16 CFR 1505.8 - Maximum acceptable material temperatures.
2010-01-01
... Association, 155 East 44th Street, New York, NY 10017. Material Degrees C. Degrees F. Capacitors (1) (1) Class... capacitor has no marked temperature limit, the maximum acceptable temperature will be assumed to be 65...
Greenslade, Thomas B., Jr.
1985-01-01
Discusses a series of experiments performed by Thomas Hope in 1805 which show the temperature at which water has its maximum density. Early data cast into a modern form as well as guidelines and recent data collected from the author provide background for duplicating Hope's experiments in the classroom. (JN)
Torque- and Speed Control of a Pitch Regulated Wind Turbine
Rasila, Mika
2003-07-01
Variable speed operated wind turbines has the potential to reduce fatigue loads, compared to fixed speed wind turbines. With pitch controllable rotor blades limitation of the power at high wind speeds is obtained. The thesis describes different controlling aspects concerning wind turbines and how these together can be used to optimize the system's performance. Torque control is used in order to achieve reduction on the mechanical loads on the drive-train for low wind speeds and limitation of power output for high wind speeds. In the high wind speed interval torque control is effective in order to limit the output power if a sufficiently fast pitch actuator is used. In the middle wind speed interval filter utilization can be used to give a reference signal to the controller in order to reduce speed and torque variations.
2007-06-01
Using a robotic telescope at the ESO La Silla Observatory, astronomers have for the first time measured the velocity of the explosions known as gamma-ray bursts. The material is travelling at the extraordinary speed of more than 99.999% of the velocity of light, the maximum speed limit in the Universe. ESO PR Photo 26a/07 ESO PR Photo 26a/07 The REM Telescope "With the development of fast-slewing ground-based telescopes such as the 0.6-m REM telescope at ESO La Silla, we can now study in great detail the very first moments following these cosmic catastrophes," says Emilio Molinari, leader of the team that made the discovery. Gamma-ray bursts (GRBs) are powerful explosions occurring in distant galaxies, that often signal the death of stars. They are so bright that, for a brief moment, they almost rival the whole Universe in luminosity. They last, however, for only a very short time, from less than a second to a few minutes. Astronomers have long known that, in order to emit such incredible power in so little time, the exploding material must be moving at a speed comparable with that of light, namely 300 000 km per second. By studying the temporal evolution of the burst luminosity, it has now been possible for the first time to precisely measure this velocity. Gamma-ray bursts, which are unseen by our eyes, are discovered by artificial satellites. The collision of the gamma-ray burst jets into the surrounding gas generates an afterglow visible in the optical and near-infrared that can radiate for several weeks. An array of robotic telescopes were built on the ground, ready to catch this vanishing emission (see e.g. ESO 17/07). On 18 April and 7 June 2006, the NASA/PPARC/ASI Swift satellite detected two bright gamma-ray bursts. In a matter of a few seconds, their position was transmitted to the ground, and the REM telescope began automatically to observe the two GRB fields, detecting the near-infrared afterglows, and monitored the evolution of their luminosity as a
A student designed experiment measuring the speed of sound as a function of altitude
Santostasi, G; Maharjan, P; McAdon, C; Nguyesn, N T; Poudel, S; Pradhan, S; Roshan, D; Wagle, M
2008-01-01
Relatively inexpensive and readily commercially available equipment (such as digital recorders, MP3 portable speakers and tie-pin microphones), allowed a team of students from McNeese State University to measure the speed of sound in the atmosphere as a function of altitude. The experiment was carried as a payload (in the context of a NASA funded student program called La-ACES) on a high altitude balloon that reached a maximum altitude of 101,000 feet. Not withstanding substantial environmental noise, our particular experimental design allowed for the filtering of the signal out of the noise, thus achieving remarkable accuracy and precision. The speed of sound measurement was then used to set limits on the abundances of the main molecular components of the atmosphere (diatomic nitrogen and oxygen). Bayesian analysis was used to set meaningful values on the uncertainty of our limits. It is our experience that students find intutive and appealing this type of probability method.
Maximum Genus of Strong Embeddings
Er-ling Wei; Yan-pei Liu; Han Ren
2003-01-01
The strong embedding conjecture states that any 2-connected graph has a strong embedding on some surface. It implies the circuit double cover conjecture: Any 2-connected graph has a circuit double cover.Conversely, it is not true. But for a 3-regular graph, the two conjectures are equivalent. In this paper, a characterization of graphs having a strong embedding with exactly 3 faces, which is the strong embedding of maximum genus, is given. In addition, some graphs with the property are provided. More generally, an upper bound of the maximum genus of strong embeddings of a graph is presented too. Lastly, it is shown that the interpolation theorem is true to planar Halin graph.
Remizov, Ivan D
2009-01-01
In this note, we represent a subdifferential of a maximum functional defined on the space of all real-valued continuous functions on a given metric compact set. For a given argument, $f$ it coincides with the set of all probability measures on the set of points maximizing $f$ on the initial compact set. This complete characterization lies in the heart of several important identities in microeconomics, such as Roy's identity, Sheppard's lemma, as well as duality theory in production and linear programming.
Senjyu, Tomonobu; Ochi, Yasutaka; Kikunaga, Yasuaki; Tokudome, Motoki; Yona, Atsushi; Muhando, Endusa Billy; Urasaki, Naomitsu [Department of Electrical and Electronics Engineering, Faculty of Engineering, University of the Ryukyus, 1 Senbaru, Nishihara-cho, Nakagami, Okinawa 903-0213 (Japan); Funabashi, Toshihisa [Meidensha Corporation, ThinkPark Tower, 2-1-1, Ohsaki, Shinagawa-ku, Tokyo 141-6029 (Japan)
2009-04-15
This paper proposes a technique that determines the optimal windmill operation speed and the optimal rotor flux. Moreover, the position and speed sensor-less wind generation system using the electromotive voltage observer to estimate rotor position and full-order observer to estimate rotor speed and the windmill output torque are proposed. The position and speed sensor-less maximum power point of wind power generation system is controlled by using the above estimated values, optimized windmill operation speed for maximum output power and optimized rotor flux for minimum generator losses. The effectiveness of the position and speed sensor-less maximum power point tracking control for wind power generation system with squirrel cage induction generator is verified by simulations. The simulation results confirm that the proposed method can estimate the operation speed efficiently. (author)
Alternative Multiview Maximum Entropy Discrimination.
Chao, Guoqing; Sun, Shiliang
2016-07-01
Maximum entropy discrimination (MED) is a general framework for discriminative estimation based on maximum entropy and maximum margin principles, and can produce hard-margin support vector machines under some assumptions. Recently, the multiview version of MED multiview MED (MVMED) was proposed. In this paper, we try to explore a more natural MVMED framework by assuming two separate distributions p1( Θ1) over the first-view classifier parameter Θ1 and p2( Θ2) over the second-view classifier parameter Θ2 . We name the new MVMED framework as alternative MVMED (AMVMED), which enforces the posteriors of two view margins to be equal. The proposed AMVMED is more flexible than the existing MVMED, because compared with MVMED, which optimizes one relative entropy, AMVMED assigns one relative entropy term to each of the two views, thus incorporating a tradeoff between the two views. We give the detailed solving procedure, which can be divided into two steps. The first step is solving our optimization problem without considering the equal margin posteriors from two views, and then, in the second step, we consider the equal posteriors. Experimental results on multiple real-world data sets verify the effectiveness of the AMVMED, and comparisons with MVMED are also reported.
46 CFR 154.1864 - Vessel speed within speed reduction.
2010-10-01
... 46 Shipping 5 2010-10-01 2010-10-01 false Vessel speed within speed reduction. 154.1864 Section... Vessel speed within speed reduction. The master shall ensure that the speed of the vessel is not greater than the posted speed reduction....
Industry guidelines for the calibration of maximum anemometers
Bailey, B.H. [AWS Scientific, Inc., Albany, NY (United States)
1996-12-31
The purpose of this paper is to report on a framework of guidelines for the calibration of the Maximum Type 40 anemometer. This anemometer model is the wind speed sensor of choice in the majority of wind resource assessment programs in the U.S. These guidelines were established by the Utility Wind Resource Assessment Program. In addition to providing guidelines for anemometers, the appropriate use of non-calibrated anemometers is also discussed. 14 refs., 1 tab.
14 CFR 29.1505 - Never-exceed speed.
2010-01-01
... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Never-exceed speed. 29.1505 Section 29.1505....1505 Never-exceed speed. (a) The never-exceed speed, V NE, must be established so that it is— (1) Not less than 40 knots (CAS); and (2) Not more than the lesser of— (i) 0.9 times the maximum forward...
14 CFR 27.1505 - Never-exceed speed.
2010-01-01
... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Never-exceed speed. 27.1505 Section 27.1505... Never-exceed speed. (a) The never-exceed speed, VNE, must be established so that it is— (1) Not less than 40 knots (CAS); and (2) Not more than the lesser of— (i) 0.9 times the maximum forward...
Automatic maximum entropy spectral reconstruction in NMR.
Mobli, Mehdi; Maciejewski, Mark W; Gryk, Michael R; Hoch, Jeffrey C
2007-10-01
Developments in superconducting magnets, cryogenic probes, isotope labeling strategies, and sophisticated pulse sequences together have enabled the application, in principle, of high-resolution NMR spectroscopy to biomolecular systems approaching 1 megadalton. In practice, however, conventional approaches to NMR that utilize the fast Fourier transform, which require data collected at uniform time intervals, result in prohibitively lengthy data collection times in order to achieve the full resolution afforded by high field magnets. A variety of approaches that involve nonuniform sampling have been proposed, each utilizing a non-Fourier method of spectrum analysis. A very general non-Fourier method that is capable of utilizing data collected using any of the proposed nonuniform sampling strategies is maximum entropy reconstruction. A limiting factor in the adoption of maximum entropy reconstruction in NMR has been the need to specify non-intuitive parameters. Here we describe a fully automated system for maximum entropy reconstruction that requires no user-specified parameters. A web-accessible script generator provides the user interface to the system.
Small scale wind energy harvesting with maximum power tracking
Joaquim Azevedo
2015-07-01
Full Text Available It is well-known that energy harvesting from wind can be used to power remote monitoring systems. There are several studies that use wind energy in small-scale systems, mainly with wind turbine vertical axis. However, there are very few studies with actual implementations of small wind turbines. This paper compares the performance of horizontal and vertical axis wind turbines for energy harvesting on wireless sensor network applications. The problem with the use of wind energy is that most of the time the wind speed is very low, especially at urban areas. Therefore, this work includes a study on the wind speed distribution in an urban environment and proposes a controller to maximize the energy transfer to the storage systems. The generated power is evaluated by simulation and experimentally for different load and wind conditions. The results demonstrate the increase in efficiency of wind generators that use maximum power transfer tracking, even at low wind speeds.
Maximum Spectral Luminous Efficacy of White Light
Murphy, T W
2013-01-01
As lighting efficiency improves, it is useful to understand the theoretical limits to luminous efficacy for light that we perceive as white. Independent of the efficiency with which photons are generated, there exists a spectrally-imposed limit to the luminous efficacy of any source of photons. We find that, depending on the acceptable bandpass and---to a lesser extent---the color temperature of the light, the ideal white light source achieves a spectral luminous efficacy of 250--370 lm/W. This is consistent with previous calculations, but here we explore the maximum luminous efficacy as a function of photopic sensitivity threshold, color temperature, and color rendering index; deriving peak performance as a function of all three parameters. We also present example experimental spectra from a variety of light sources, quantifying the intrinsic efficacy of their spectral distributions.
Development of a speeding-related crash typology.
Council, F.M. Reurings, M. Srinivasan, R. Masten, S. & Carter, C.
2010-01-01
Speeding, the driver behaviour of exceeding the posted speed limit or driving too fast for conditions, has consistently been estimated to be a contributing factor to a significant percentage of fatal and nonfatal crashes. The U.S. Department of Transportation has instituted the Speed Management Stra
14 CFR 25.1513 - Minimum control speed.
2010-01-01
... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Minimum control speed. 25.1513 Section 25.1513 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... Limitations § 25.1513 Minimum control speed. The minimum control speed V MC determined under § 25.149 must...
Brax, Philippe; Davis, Anne-Christine
2015-01-01
We analyse the speed of gravitational waves in coupled Galileon models with an equation of state $\\omega_\\phi=-1$ now and a ghost-free Minkowski limit. We find that the gravitational waves propagate much faster than the speed of light unless these models are small perturbations of cubic Galileons and the Galileon energy density is sub-dominant to a dominant cosmological constant. In this case, the binary pulsar bounds on the speed of gravitational waves can be satisfied and the equation of state can be close to -1 when the coupling to matter and the coefficient of the cubic term of the Galileon Lagrangian are related. This severely restricts the allowed cosmological behaviour of Galileon models and we are forced to conclude that Galileons with a stable Minkowski limit cannot account for the observed acceleration of the expansion of the universe on their own. Moreover any sub-dominant Galileon component of our universe must be dominated by the cubic term. For such models with gravitons propagating faster than ...
Compass gait mechanics account for top walking speeds in ducks and humans.
Usherwood, James R; Szymanek, Katie L; Daley, Monica A
2008-12-01
The constraints to maximum walking speed and the underlying cause of the walk-run transition remains controversial. However, the motions of the body and legs can be reduced to a few mechanical principles, which, if valid, impose simple physics-based limits to walking speed. Bipedal walking may be viewed as a vaulting gait, with the centre of mass (CoM) passing over a stiff stance leg (an 'inverted pendulum'), while the swing leg swings forward (as a pendulum). At its simplest, this forms a 'compass gait' walker, which has a maximum walking speed constrained by simple mechanics: walk too fast, or with too high a step length, and gravity fails to keep the stance foot attached to the floor. But how useful is such an extremely reductionist model? In the present study, we report measurements on a range of duck breeds as example unspecialized, non-planar, crouch-limbed walkers and contrast these findings with previous measurements on humans, using the theoretical framework of compass gait walking. Ducks walked as inverted pendulums with near-passive swing legs up to relative velocities around 0.5, remarkably consistent with the theoretical model. By contrast, top walking speeds in humans cannot be achieved with passive swing legs: humans, while still constrained by compass gait mechanics, extend their envelope of walking speeds by using relatively high step frequencies. Therefore, the capacity to drive the swing leg forward by walking humans may be a specialization for walking, allowing near-passive vaulting of the CoM at walking speeds 4/3 that possible with a passive (duck-like) swing leg.
Cacti with maximum Kirchhoff index
Wang, Wen-Rui; Pan, Xiang-Feng
2015-01-01
The concept of resistance distance was first proposed by Klein and Randi\\'c. The Kirchhoff index $Kf(G)$ of a graph $G$ is the sum of resistance distance between all pairs of vertices in $G$. A connected graph $G$ is called a cactus if each block of $G$ is either an edge or a cycle. Let $Cat(n;t)$ be the set of connected cacti possessing $n$ vertices and $t$ cycles, where $0\\leq t \\leq \\lfloor\\frac{n-1}{2}\\rfloor$. In this paper, the maximum kirchhoff index of cacti are characterized, as well...
Generic maximum likely scale selection
Pedersen, Kim Steenstrup; Loog, Marco; Markussen, Bo
2007-01-01
The fundamental problem of local scale selection is addressed by means of a novel principle, which is based on maximum likelihood estimation. The principle is generally applicable to a broad variety of image models and descriptors, and provides a generic scale estimation methodology. The focus...... on second order moments of multiple measurements outputs at a fixed location. These measurements, which reflect local image structure, consist in the cases considered here of Gaussian derivatives taken at several scales and/or having different derivative orders....
Elvik, Rune
2015-01-01
This paper probes the relationship between changes in the risk of apprehension for speeding in Norway and changes in the amount of speeding. The paper is based on a game-theoretic model of how the rate of violations and the amount of enforcement is determined by the interaction between drivers...
Fosgerau, Mogens
2005-01-01
between speed and income is found again in the empirical analysis of a cross-sectional dataset comprising 60,000 observations of car trips. This is used to perform regressions of speed on income, distance travelled, and a number of controls. The results are clearly statistically significant and indicate...
无
2011-01-01
The 1,318-km Beijing-Shanghai High-Speed Railway will finally come into operation at the end of June.Since construction began three years ago,the speedy railway has grabbed worldwide attention because of its design as the world’s longest and fastesthigh-speed rail line utilizing the most advanced technology.
Effectiveness of Motorcycle speed controlled by speed hump
Pornsiri Urapa
2014-09-01
Full Text Available Speed humps are one of the traffic calming measures widely accepted to control vehicle speed in the local road. Humps standards from the western countries are designed mainly for the passenger car. This study, therefore, aims to reveal the effectiveness of speed hump to control the motorcycle speed. This study observes the free-flow speed of the riders at the total of 20 speed bumps and humps. They are 0.3-14.8 meter in width and 5-18 centimeter in height. The results reveal that the 85th percentile speeds reduce 15-65 percent when crossing the speed bumps and speed humps. Besides, this study develops the speed model to predict the motorcycle mean speed and 85th percentile speed. It is found that speed humps follow the ITE standard can control motorcycle crossing speeds to be 25-30 Kph which are suitable to travel on the local road.
30 CFR 7.87 - Test to determine the maximum fuel-air ratio.
2010-07-01
... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Test to determine the maximum fuel-air ratio. 7... Use in Underground Coal Mines § 7.87 Test to determine the maximum fuel-air ratio. (a) Test procedure... several speed/torque conditions to determine the concentrations of CO and NOX, dry basis, in the...
24 CFR 941.306 - Maximum project cost.
2010-04-01
...) project costs that are subject to the TDC limit (i.e., Housing Construction Costs and Community Renewal Costs); and (2) project costs that are not subject to the TDC limit (i.e., Additional Project Costs... expended for the project, and this becomes the maximum project cost for purposes of the ACC. (b) TDC...
Economics and Maximum Entropy Production
Lorenz, R. D.
2003-04-01
Price differentials, sales volume and profit can be seen as analogues of temperature difference, heat flow and work or entropy production in the climate system. One aspect in which economic systems exhibit more clarity than the climate is that the empirical and/or statistical mechanical tendency for systems to seek a maximum in production is very evident in economics, in that the profit motive is very clear. Noting the common link between 1/f noise, power laws and Self-Organized Criticality with Maximum Entropy Production, the power law fluctuations in security and commodity prices is not inconsistent with the analogy. There is an additional thermodynamic analogy, in that scarcity is valued. A commodity concentrated among a few traders is valued highly by the many who do not have it. The market therefore encourages via prices the spreading of those goods among a wider group, just as heat tends to diffuse, increasing entropy. I explore some empirical price-volume relationships of metals and meteorites in this context.
14 CFR 25.1511 - Flap extended speed.
2010-01-01
... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Flap extended speed. 25.1511 Section 25... Limitations § 25.1511 Flap extended speed. The established flap extended speed V FE must be established so that it does not exceed the design flap speed V F chosen under §§ 25.335(e) and 25.345, for...
OVER SPEED VIOLATION MANAGEMENT OF A VEHICLE THROUGH ZIGBEE
Uma Makeswari.A; Rubini.R
2013-01-01
In the present day scenario traffic rules are frequently violated by the drivers and over speeding occur due to bad driving behavior. So, a driver assistance system is provided to prevent over speeding,violation of road rules and also to display alert messages. The proposed system has an alerting, recording and reporting system for over speed violation management. The Zigbee transmitter sends the speed limit of the particular lane entered by the vehicle and also gives alerts like “road works”...
Capacity factors of a mixed speed railway network
Harrod, Steven
2009-01-01
Fifty-four combinations of track network and speed differential are evaluated within a linear, discrete time network model that maximizes an objective function of train volume, delays, and idle train time. The results contradict accepted dispatching practice by suggesting that when introducing...... a priority, high-speed train onto a network, maximum network now is attained when the priority train operates at maximum speed. in addition, increasing siding capacity at meeting points may offer a network capacity improvement comparable to partial double track. (C) 2009 Elsevier Ltd. All rights reserved....
Maximum life spiral bevel reduction design
Savage, M.; Prasanna, M. G.; Coe, H. H.
1992-07-01
Optimization is applied to the design of a spiral bevel gear reduction for maximum life at a given size. A modified feasible directions search algorithm permits a wide variety of inequality constraints and exact design requirements to be met with low sensitivity to initial values. Gear tooth bending strength and minimum contact ratio under load are included in the active constraints. The optimal design of the spiral bevel gear reduction includes the selection of bearing and shaft proportions in addition to gear mesh parameters. System life is maximized subject to a fixed back-cone distance of the spiral bevel gear set for a specified speed ratio, shaft angle, input torque, and power. Significant parameters in the design are: the spiral angle, the pressure angle, the numbers of teeth on the pinion and gear, and the location and size of the four support bearings. Interpolated polynomials expand the discrete bearing properties and proportions into continuous variables for gradient optimization. After finding the continuous optimum, a designer can analyze near optimal designs for comparison and selection. Design examples show the influence of the bearing lives on the gear parameters in the optimal configurations. For a fixed back-cone distance, optimal designs with larger shaft angles have larger service lives.
Time optimal paths for a constant speed unicycle
Reister, D.B.
1991-01-01
This paper uses the Pontryagin maximum principle to find time optimal paths for a constant speed unicycle. The time optimal paths consist of sequences of arcs of circles and straight lines. The maximum principle introduced concepts (dual variables, bang-bang solutions, singular solutions, and transversality conditions) that provide important insight into the nature of the time optimal paths. 10 refs., 6 figs.
Adaptation of feed rate for 3-axis CNC high-speed machining
ZHANG De-li; ZHOU Lai-shui
2009-01-01
To improve the efficiency of CNC machining, assumptive transit circular arc is used to contour two adjacent moves together on the corner to make smooth paths. The radius of transit circular arc can be adjusted with contour accuracy, and the feed rate on the corner can be controlled through limiting the maximum feed rate of transit circular arc segment. A look-ahead algorithm for a series of moves is proposed for speed adjustment in advance, which avoids the occurrence of overload of cutting tool on the corner and reduces the servo track error of parts on the corner or of circular arc move. Equivalent trapezoidal velocity profile is used to analyze the speed of S-curve velocity profile and work out its accurate interpolation, which overcomes the disadvantage of looking up table to calculate feed rate approximately, hence high accuracy and fine surface quality can be obtained while the machining speed is high. The proposed methods can meet the requirements of real-time analysis of high-speed machining. The presented algorithm is effective and has been adopted by CNC system of newly developed high-speed milling machine.
INTELLIGENT SPEED ADAPTATION (ISA AND ROAD SAFETY
H.L. OEI, M.Sc.
2002-01-01
Full Text Available An ISA system consists of GPS to determine the car's position, a CD-ROM in the car containing information of a road network including the prevailing speed limit of each road section, and feedback to the driver. Experiments in Sweden are testing several options, from warning the driver to a resisting force exerted by the accelerator pedal that can be countered by the driver. In the Netherlands the system intervenes so the limit cannot be exceeded. Experiments in Sweden have recently been concluded and an evaluation is in progress. In the Netherlands the project was concluded early 2001. The field experiments so far mainly concern the measure of acceptance of the system(s by the public. Several simulation studies have also been conducted. Little is known as yet from practical research of the effects of ISA on road safety, though a large safety potential is assumed. For the Dutch situation, based on the assumption that all passenger cars are fitted with ISA and an assumed speed distribution as the result of ISA, a theoretical calculation is made of the effects of ISA on speed and safety. The result is an estimated reduction of road casualties of 25 to 30%. Further, the assumed speed distribution is validated with field measurements of the experiment in the city of Tilburg. The result is that the measured average speed of the speed distribution fits quite well with the calculated average speed.
Map Matching for Intelligent Speed Adaptation
Tradisauskas, Nerius; Juhl, Jens; Lahrmann, Harry;
2007-01-01
The availability of Global Navigation Satellite Systems enables sophisticated vehicle guidance and advisory systems such as Intelligent Speed Adaptation (ISA) systems. In ISA systems, it is essential to be able to position vehicles within a road network. Because digital road networks as well as GPS...... positioning are often inaccurate, a technique known as map matching is needed that aims to use this inaccurate data for determining a vehicle's real road-network position. Then, knowing this position, an ISA system can compare the vehicle's speed with the speed limit in effect and react appropriately...
Higham, Timothy E; Korchari, Paul G; McBrayer, Lance D
2011-05-15
Maximum locomotor performance is crucial for capturing prey, escaping predators and many other behaviors. However, we know little about what defines maximum performance in vertebrates. Muscles drive the movement of the limbs during locomotion, and thus likely play a major role in defining locomotor capacity. For lizards, the iliofibularis, a swing-phase muscle, is often linked to ecology and/or performance. However, stance-phase muscles likely limit performance given that they propel the animal. Using a small semi-arboreal lizard (Sceloporus woodi), we compared how swing- and stance-phase muscles relate to maximum running speed and acceleration. We employed both a level and vertical trackway to elicit ecologically relevant locomotor performance. Six individuals were filmed at 250 frames s⁻¹ in lateral view. Following performance trials, upper and lower hindlimbs were sectioned and assessed using histochemistry. Fast glycolytic, fast oxidative and slow oxidative fibers were detected and counted in the gastrocnemius (GA; stance phase) and iliofibularis (IF; swing phase) muscles. In addition, the mean fiber diameter for each fiber type in each muscle was determined, as was the fiber cross-sectional area. We found that properties of the GA, but not the IF, were positively correlated with performance. Interestingly, certain attributes of the GA were correlated with maximum vertical locomotion whereas others were correlated with maximum level locomotion. We conclude that stance phase, not swing phase, limits maximum performance in this species of lizard. In addition, we highlight the need to include properties of stance-phase muscles and a spectrum of ecologically relevant behaviors when attempting to correlate locomotor physiology with ecology and/or performance.
Physical limits on ground motion at Yucca Mountain
Andrews, D.J.; Hanks, T.C.; Whitney, J.W.
2007-01-01
Physical limits on possible maximum ground motion at Yucca Mountain, Nevada, the designated site of a high-level radioactive waste repository, are set by the shear stress available in the seismogenic depth of the crust and by limits on stress change that can propagate through the medium. We find in dynamic deterministic 2D calculations that maximum possible horizontal peak ground velocity (PGV) at the underground repository site is 3.6 m/sec, which is smaller than the mean PGV predicted by the probabilistic seismic hazard analysis (PSHA) at annual exceedance probabilities less than 10-6 per year. The physical limit on vertical PGV, 5.7 m/sec, arises from supershear rupture and is larger than that from the PSHA down to 10-8 per year. In addition to these physical limits, we also calculate the maximum ground motion subject to the constraint of known fault slip at the surface, as inferred from paleoseismic studies. Using a published probabilistic fault displacement hazard curve, these calculations provide a probabilistic hazard curve for horizontal PGV that is lower than that from the PSHA. In all cases the maximum ground motion at the repository site is found by maximizing constructive interference of signals from the rupture front, for physically realizable rupture velocity, from all parts of the fault. Vertical PGV is maximized for ruptures propagating near the P-wave speed, and horizontal PGV is maximized for ruptures propagating near the Rayleigh-wave speed. Yielding in shear with a Mohr-Coulomb yield condition reduces ground motion only a modest amount in events with supershear rupture velocity, because ground motion consists primarily of P waves in that case. The possibility of compaction of the porous unsaturated tuffs at the higher ground-motion levels is another attenuating mechanism that needs to be investigated.
Speed Management Strategies; A Systematic Review
Homayoun Sadeghi-Bazargani
2016-07-01
Full Text Available Objective: To systematically identify the various methods of speed management and their effects. Methods: A systematic search was performed in Science Direct, Ovid Medline, Scopus, PubMed and ProQuest databases from April to June 2015. Hand searching and reference of selected articles were used to improve article identification. Articles published after 1990 which had reported on efficacy/effectiveness of speed management strategies were included. Data were extracted using pre-defined extraction table. Results: Of the 803 retrieved articles, 22 articles were included in this review. Most of the included articles (63% had before-after design and were done in European countries. Speed cameras, engineering schemes, intelligent speed adaption (ISA, speed limits and zones, vehicle activated sign and integrated strategies were the most common strategies reported in the literature. Various strategies had different effects on mean speed of the vehicles ranging from 1.6 to 10 km/h. Moreover, 8-65% and 11-71% reduction was reported in person injured accidents and fatal accidents, respectively as a result of employing various strategies. Conclusion: Literature revealed positive effects of various speed management strategies. Using various strategies was mostly dependent on road characteristics, driver’s attitude about the strategy as well as economic and technological capabilities of the country. Political support is considered as a main determinant in selecting speed management strategies.
Objects of maximum electromagnetic chirality
Fernandez-Corbaton, Ivan
2015-01-01
We introduce a definition of the electromagnetic chirality of an object and show that it has an upper bound. The upper bound is attained if and only if the object is transparent for fields of one handedness (helicity). Additionally, electromagnetic duality symmetry, i.e. helicity preservation upon scattering, turns out to be a necessary condition for reciprocal scatterers to attain the upper bound. We use these results to provide requirements for the design of such extremal scatterers. The requirements can be formulated as constraints on the polarizability tensors for dipolar scatterers or as material constitutive relations. We also outline two applications for objects of maximum electromagnetic chirality: A twofold resonantly enhanced and background free circular dichroism measurement setup, and angle independent helicity filtering glasses.
Maximum mutual information regularized classification
Wang, Jim Jing-Yan
2014-09-07
In this paper, a novel pattern classification approach is proposed by regularizing the classifier learning to maximize mutual information between the classification response and the true class label. We argue that, with the learned classifier, the uncertainty of the true class label of a data sample should be reduced by knowing its classification response as much as possible. The reduced uncertainty is measured by the mutual information between the classification response and the true class label. To this end, when learning a linear classifier, we propose to maximize the mutual information between classification responses and true class labels of training samples, besides minimizing the classification error and reducing the classifier complexity. An objective function is constructed by modeling mutual information with entropy estimation, and it is optimized by a gradient descend method in an iterative algorithm. Experiments on two real world pattern classification problems show the significant improvements achieved by maximum mutual information regularization.
The strong maximum principle revisited
Pucci, Patrizia; Serrin, James
In this paper we first present the classical maximum principle due to E. Hopf, together with an extended commentary and discussion of Hopf's paper. We emphasize the comparison technique invented by Hopf to prove this principle, which has since become a main mathematical tool for the study of second order elliptic partial differential equations and has generated an enormous number of important applications. While Hopf's principle is generally understood to apply to linear equations, it is in fact also crucial in nonlinear theories, such as those under consideration here. In particular, we shall treat and discuss recent generalizations of the strong maximum principle, and also the compact support principle, for the case of singular quasilinear elliptic differential inequalities, under generally weak assumptions on the quasilinear operators and the nonlinearities involved. Our principal interest is in necessary and sufficient conditions for the validity of both principles; in exposing and simplifying earlier proofs of corresponding results; and in extending the conclusions to wider classes of singular operators than previously considered. The results have unexpected ramifications for other problems, as will develop from the exposition, e.g. two point boundary value problems for singular quasilinear ordinary differential equations (Sections 3 and 4); the exterior Dirichlet boundary value problem (Section 5); the existence of dead cores and compact support solutions, i.e. dead cores at infinity (Section 7); Euler-Lagrange inequalities on a Riemannian manifold (Section 9); comparison and uniqueness theorems for solutions of singular quasilinear differential inequalities (Section 10). The case of p-regular elliptic inequalities is briefly considered in Section 11.
Subotić Jovana Lj.
2014-01-01
Full Text Available Speed, and vehicles themselves, affect the level of service and road safety, quality of life, noise from traffic, the environment, health, air pollution, emission of carbon dioxide, global warming, the economy and consumption of non-renewable energy such as oil. Therefore, the speed management of the traffic of multiple significance and that should be primarily to provide effective and economical conditions of the modern and preventive protection of human life as the greatest treasure and then the material resources. The way to accomplish this is by using various (different measures such as: appropriate planning and projecting roads and streets, speed control, the legislation, enforcement, campaigns, education, advanced technologies (ITS.
Godovaniouk V. N.
2011-08-01
Full Text Available The design of a gas speed flow transducer using the coupling of gas speed and heat streams within the transducer itself is proposed. To maintain the heat balance between two thermoresistors under gas stream at different temperatures, it provides energy consumption monitoring. The detailed combined planar technology for the transducer production is presented. The worked-out measurement procedure allows to make measurements in the temperature range. Information enough to organize production of cheap, reliable and precise gas speed flow transducers is given.
Lü Xiaoqing; Cao Biao; Zeng Min; Huang Zenghao
2005-01-01
Aim at improving the stability of the Short-circuiting Gas Metal Arc Welding ( GMA W-S) process for the enhanced speed usage, effects of current waveform parameters during short-term on the welding stability have been investigated by experimental method. The welding power source used for the research is an inverter with a special current waveform control. It is shown that the spatter decreases at first then increases with each increase of the low current period, current increase rate and the maximum current limit. The test results are provided for welding of 1 mm and 3 mm mild steel at speed of 1.2 m/min. The stable GMA W-S process under high speed welding condition has been achieved by optimizing the parameters.
Bo Yang, Lingen Chen, Fengrui Sun
2011-11-01
Full Text Available Performance of an endoreversible Carnot heat pump cycle with finite speed of the piston is investigated by using finite time thermodynamics. The analytical formulae between the optimal heating load and the coefficient of performance (COP, as well as between the optimal heating load and speed ratio of the piston are derived. It is found that the heating load versus COP characteristics are parabolic-like, and there exist a maximum heating load and the corresponding COP. These are different from the monotonically decreasing characteristic of the endoreversible Carnot heat pump without consideration of the finite speed of the piston. At the same time, the effects of reservoir temperature ratio on the optimal relations are analyzed by numerical examples. In the analysis and optimization, two cases with and without limit of cycle period are included.
Speed of the internal pellet target in CSRm
无
2009-01-01
Pellet target is one of the main candidate targets in CSRm (cooler storage ring’s main ring) for hadron physics studies. Pellet speed is an important physical parameter for the target. Larger pellet speed could shorten the interacting time interval between the pellet and the cyclotron beam, and thus results in a small temperature variation for the pellet. This could make the pellet facility work in a stable condition. A fluid dynamic simulation was carried out for the pellet speed, and it was found that the maximum speed for the target pellet may be restricted to about 100 m/s even if all working parameters were set to their optimal values.
Time optimal paths for high speed maneuvering
Reister, D.B.; Lenhart, S.M.
1993-01-01
Recent theoretical results have completely solved the problem of determining the minimum length path for a vehicle with a minimum turning radius moving from an initial configuration to a final configuration. Time optimal paths for a constant speed vehicle are a subset of the minimum length paths. This paper uses the Pontryagin maximum principle to find time optimal paths for a constant speed vehicle. The time optimal paths consist of sequences of axes of circles and straight lines. The maximum principle introduces concepts (dual variables, bang-bang solutions, singular solutions, and transversality conditions) that provide important insight into the nature of the time optimal paths. We explore the properties of the optimal paths and present some experimental results for a mobile robot following an optimal path.
Efficiency at Maximum Power of Interacting Molecular Machines
Golubeva, Natalia; Imparato, Alberto
2012-01-01
We investigate the efficiency of systems of molecular motors operating at maximum power. We consider two models of kinesin motors on a microtubule: for both the simplified and the detailed model, we find that the many-body exclusion effect enhances the efficiency at maximum power of the many- motor...... system, with respect to the single motor case. Remarkably, we find that this effect occurs in a limited region of the system parameters, compatible with the biologically relevant range....
National Oceanic and Atmospheric Administration, Department of Commerce — This data set included wind speeds for each subregion in the study (Georges Bank, Gulf of Maine, Southern New England, Middle Atlantic Bight) . The data came from...
无
2007-01-01
@@ 2007 was an excellent year for the transportation industry, marked by high speed railway transportation, development of the national expressway network and launch of the Chang'e lunar probe satellite.
Kaufmann, Tobias; Kübler, Andrea
2014-10-01
Objective. The speed of brain-computer interfaces (BCI), based on event-related potentials (ERP), is inherently limited by the commonly used one-stimulus paradigm. In this paper, we introduce a novel paradigm that can increase the spelling speed by a factor of 2, thereby extending the one-stimulus paradigm to a two-stimulus paradigm. Two different stimuli (a face and a symbol) are presented at the same time, superimposed on different characters and ERPs are classified using a multi-class classifier. Here, we present the proof-of-principle that is achieved with healthy participants. Approach. Eight participants were confronted with the novel two-stimulus paradigm and, for comparison, with two one-stimulus paradigms that used either one of the stimuli. Classification accuracies (percentage of correctly predicted letters) and elicited ERPs from the three paradigms were compared in a comprehensive offline analysis. Main results. The accuracies slightly decreased with the novel system compared to the established one-stimulus face paradigm. However, the use of two stimuli allowed for spelling at twice the maximum speed of the one-stimulus paradigms, and participants still achieved an average accuracy of 81.25%. This study introduced an alternative way of increasing the spelling speed in ERP-BCIs and illustrated that ERP-BCIs may not yet have reached their speed limit. Future research is needed in order to improve the reliability of the novel approach, as some participants displayed reduced accuracies. Furthermore, a comparison to the most recent BCI systems with individually adjusted, rapid stimulus timing is needed to draw conclusions about the practical relevance of the proposed paradigm. Significance. We introduced a novel two-stimulus paradigm that might be of high value for users who have reached the speed limit with the current one-stimulus ERP-BCI systems.
High speed heterostructure devices
Beer, Albert C; Willardson, R K; Kiehl, Richard A; Sollner, T C L Gerhard
1994-01-01
Volume 41 includes an in-depth review of the most important, high-speed switches made with heterojunction technology. This volume is aimed at the graduate student or working researcher who needs a broad overview andan introduction to current literature. Key Features * The first complete review of InP-based HFETs and complementary HFETs, which promise very low power and high speed * Offers a complete, three-chapter review of resonant tunneling * Provides an emphasis on circuits as well as devices.
Maximum frequency of the decametric radiation from Jupiter
Barrow, C. H.; Alexander, J. K.
1980-01-01
The upper frequency limits of Jupiter's decametric radio emission are found to be essentially the same when observed from the earth or, with considerably higher sensitivity, from the Voyager spacecraft close to Jupiter. This suggests that the maximum frequency is a real cut-off corresponding to a maximum gyrofrequency of about 38-40 MHz at Jupiter. It no longer appears to be necessary to specify different cut-off frequencies for the Io and non-Io emission as the maximum frequencies are roughly the same in each case.
Maximum entropy production in daisyworld
Maunu, Haley A.; Knuth, Kevin H.
2012-05-01
Daisyworld was first introduced in 1983 by Watson and Lovelock as a model that illustrates how life can influence a planet's climate. These models typically involve modeling a planetary surface on which black and white daisies can grow thus influencing the local surface albedo and therefore also the temperature distribution. Since then, variations of daisyworld have been applied to study problems ranging from ecological systems to global climate. Much of the interest in daisyworld models is due to the fact that they enable one to study self-regulating systems. These models are nonlinear, and as such they exhibit sensitive dependence on initial conditions, and depending on the specifics of the model they can also exhibit feedback loops, oscillations, and chaotic behavior. Many daisyworld models are thermodynamic in nature in that they rely on heat flux and temperature gradients. However, what is not well-known is whether, or even why, a daisyworld model might settle into a maximum entropy production (MEP) state. With the aim to better understand these systems, this paper will discuss what is known about the role of MEP in daisyworld models.
Maximum Matchings via Glauber Dynamics
Jindal, Anant; Pal, Manjish
2011-01-01
In this paper we study the classic problem of computing a maximum cardinality matching in general graphs $G = (V, E)$. The best known algorithm for this problem till date runs in $O(m \\sqrt{n})$ time due to Micali and Vazirani \\cite{MV80}. Even for general bipartite graphs this is the best known running time (the algorithm of Karp and Hopcroft \\cite{HK73} also achieves this bound). For regular bipartite graphs one can achieve an $O(m)$ time algorithm which, following a series of papers, has been recently improved to $O(n \\log n)$ by Goel, Kapralov and Khanna (STOC 2010) \\cite{GKK10}. In this paper we present a randomized algorithm based on the Markov Chain Monte Carlo paradigm which runs in $O(m \\log^2 n)$ time, thereby obtaining a significant improvement over \\cite{MV80}. We use a Markov chain similar to the \\emph{hard-core model} for Glauber Dynamics with \\emph{fugacity} parameter $\\lambda$, which is used to sample independent sets in a graph from the Gibbs Distribution \\cite{V99}, to design a faster algori...
2011-01-10
...: Establishing Maximum Allowable Operating Pressure or Maximum Operating Pressure Using Record Evidence, and... facilities of their responsibilities, under Federal integrity management (IM) regulations, to perform... system, especially when calculating Maximum Allowable Operating Pressure (MAOP) or Maximum Operating...
Maximum Velocities in Flexion and Extension Actions for Sport
Jessop David M.
2016-04-01
Full Text Available Speed of movement is fundamental to the outcome of many human actions. A variety of techniques can be implemented in order to maximise movement speed depending on the goal of the movement, constraints, and the time available. Knowing maximum movement velocities is therefore useful for developing movement strategies but also as input into muscle models. The aim of this study was to determine maximum flexion and extension velocities about the major joints in upper and lower limbs. Seven university to international level male competitors performed flexion/extension at each of the major joints in the upper and lower limbs under three conditions: isolated; isolated with a countermovement; involvement of proximal segments. 500 Hz planar high speed video was used to calculate velocities. The highest angular velocities in the upper and lower limb were 50.0 rad·s-1 and 28.4 rad·s-1, at the wrist and knee, respectively. As was true for most joints, these were achieved with the involvement of proximal segments, however, ANOVA analysis showed few significant differences (p<0.05 between conditions. Different segment masses, structures and locations produced differing results, in the upper and lower limbs, highlighting the requirement of segment specific strategies for maximal movements.
Minetti, Alberto E; Boldrini, Lorenzo; Brusamolin, Laura; Zamparo, Paola; McKee, Tom
2003-08-01
A novel apparatus, composed by a controllable treadmill, a computer, and an ultrasonic range finder, is here proposed to help investigation of many aspects of spontaneous locomotion. The acceleration or deceleration of the subject, detected by the sensor and processed by the computer, is used to accelerate or decelerate the treadmill in real time. The system has been used to assess, in eight subjects, the self-selected speed of walking and running, the maximum "reasonable" speed of walking, and the minimum reasonable speed of running at different gradients (from level up to +25%). This evidenced the speed range at which humans neither walk nor run, from 7.2 +/- 0.6 to 8.4 +/- 1.1 km/h for level locomotion, slightly narrowing at steeper slopes. These data confirm previous results, obtained indirectly from stride frequency recordings. The self-selected speed of walking decreases with increasing gradient (from 5.0 +/- 0.8 km/h at 0% to 3.0 +/- 0.9 km/h at +25%) and seems to be approximately 30% higher than the speed that minimizes the metabolic energy cost of walking, obtained from the literature, at all the investigated gradients. The advantages, limitations, and potential applications of the newly proposed methodology in physiology, biomechanics, and pathology of locomotion are discussed in this paper.
Combustion Limits and Efficiency of Turbojet Engines
Barnett, H. C.; Jonash, E. R.
1956-01-01
Combustion must be maintained in the turbojet-engine combustor over a wide range of operating conditions resulting from variations in required engine thrust, flight altitude, and flight speed. Furthermore, combustion must be efficient in order to provide the maximum aircraft range. Thus, two major performance criteria of the turbojet-engine combustor are (1) operatable range, or combustion limits, and (2) combustion efficiency. Several fundamental requirements for efficient, high-speed combustion are evident from the discussions presented in chapters III to V. The fuel-air ratio and pressure in the burning zone must lie within specific limits of flammability (fig. 111-16(b)) in order to have the mixture ignite and burn satisfactorily. Increases in mixture temperature will favor the flammability characteristics (ch. III). A second requirement in maintaining a stable flame -is that low local flow velocities exist in the combustion zone (ch. VI). Finally, even with these requirements satisfied, a flame needs a certain minimum space in which to release a desired amount of heat, the necessary space increasing with a decrease in pressure (ref. 1). It is apparent, then, that combustor design and operation must provide for (1) proper control of vapor fuel-air ratios in the combustion zone at or near stoichiometric, (2) mixture pressures above the minimum flammability pressures, (3) low flow velocities in the combustion zone, and (4) adequate space for the flame.
Variable-speed Generators with Flux Weakening
Fardoun, A. A.; Fuchs, E. F.; Carlin, P. W.
1993-01-01
A cost-competitive, permanent-magnet 20 kW generator is designed such that the following criteria are satisfied: an (over) load capability of at least 30 kW over the entire speed range of 60-120 rpm, generator weight of about 550 lbs with a maximum radial stator flux density of 0.82 T at low speed, unity power factor operation, acceptably small synchronous reactances and operation without a gear box. To justify this final design four different generator designs are investigated: the first two designs are studied to obtain a speed range from 20 to 200 rpm employing rotor field weakening, and the latter two are investigated to obtain a maximum speed range of 40 to 160 rpm based on field weakening via the stator excitation. The generator reactances and induced voltages are computed using finite element/difference solutions. Generator losses and efficiencies are presented for all four designs at rated temperature of Tr=120C.
Speed Scaling on Parallel Processors with Migration
Angel, Eric; Kacem, Fadi; Letsios, Dimitrios
2011-01-01
We study the problem of scheduling a set of jobs with release dates, deadlines and processing requirements (or works), on parallel speed-scaled processors so as to minimize the total energy consumption. We consider that both preemption and migration of jobs are allowed. An exact polynomial-time algorithm has been proposed for this problem, which is based on the Ellipsoid algorithm. Here, we formulate the problem as a convex program and we propose a simpler polynomial-time combinatorial algorithm which is based on a reduction to the maximum flow problem. Our algorithm runs in $O(nf(n)logP)$ time, where $n$ is the number of jobs, $P$ is the range of all possible values of processors' speeds divided by the desired accuracy and $f(n)$ is the complexity of computing a maximum flow in a layered graph with O(n) vertices. Independently, Albers et al. \\cite{AAG11} proposed an $O(n^2f(n))$-time algorithm exploiting the same relation with the maximum flow problem. We extend our algorithm to the multiprocessor speed scal...
The Sherpa Maximum Likelihood Estimator
Nguyen, D.; Doe, S.; Evans, I.; Hain, R.; Primini, F.
2011-07-01
A primary goal for the second release of the Chandra Source Catalog (CSC) is to include X-ray sources with as few as 5 photon counts detected in stacked observations of the same field, while maintaining acceptable detection efficiency and false source rates. Aggressive source detection methods will result in detection of many false positive source candidates. Candidate detections will then be sent to a new tool, the Maximum Likelihood Estimator (MLE), to evaluate the likelihood that a detection is a real source. MLE uses the Sherpa modeling and fitting engine to fit a model of a background and source to multiple overlapping candidate source regions. A background model is calculated by simultaneously fitting the observed photon flux in multiple background regions. This model is used to determine the quality of the fit statistic for a background-only hypothesis in the potential source region. The statistic for a background-plus-source hypothesis is calculated by adding a Gaussian source model convolved with the appropriate Chandra point spread function (PSF) and simultaneously fitting the observed photon flux in each observation in the stack. Since a candidate source may be located anywhere in the field of view of each stacked observation, a different PSF must be used for each observation because of the strong spatial dependence of the Chandra PSF. The likelihood of a valid source being detected is a function of the two statistics (for background alone, and for background-plus-source). The MLE tool is an extensible Python module with potential for use by the general Chandra user.
Vestige: Maximum likelihood phylogenetic footprinting
Maxwell Peter
2005-05-01
Full Text Available Abstract Background Phylogenetic footprinting is the identification of functional regions of DNA by their evolutionary conservation. This is achieved by comparing orthologous regions from multiple species and identifying the DNA regions that have diverged less than neutral DNA. Vestige is a phylogenetic footprinting package built on the PyEvolve toolkit that uses probabilistic molecular evolutionary modelling to represent aspects of sequence evolution, including the conventional divergence measure employed by other footprinting approaches. In addition to measuring the divergence, Vestige allows the expansion of the definition of a phylogenetic footprint to include variation in the distribution of any molecular evolutionary processes. This is achieved by displaying the distribution of model parameters that represent partitions of molecular evolutionary substitutions. Examination of the spatial incidence of these effects across regions of the genome can identify DNA segments that differ in the nature of the evolutionary process. Results Vestige was applied to a reference dataset of the SCL locus from four species and provided clear identification of the known conserved regions in this dataset. To demonstrate the flexibility to use diverse models of molecular evolution and dissect the nature of the evolutionary process Vestige was used to footprint the Ka/Ks ratio in primate BRCA1 with a codon model of evolution. Two regions of putative adaptive evolution were identified illustrating the ability of Vestige to represent the spatial distribution of distinct molecular evolutionary processes. Conclusion Vestige provides a flexible, open platform for phylogenetic footprinting. Underpinned by the PyEvolve toolkit, Vestige provides a framework for visualising the signatures of evolutionary processes across the genome of numerous organisms simultaneously. By exploiting the maximum-likelihood statistical framework, the complex interplay between mutational
An Improved Maximum C/I Scheduling Algorithm Combined with HARQ
无
2003-01-01
It is well known that traffic in downlink will be much greater than that in uplink in 3 G and that beyond. High Speed Downlink Packet Access(HSDPA) is the solution to transmission for high-speed downlink packet service in UMTS, of which Maximum C/I scheduling is one of the important algorithms related to performance enhancement. An improved scheme, Thorough Maximum C/I scheduling algorithm, is presented in this article, in which every transmitted frame has the maximum C/I. The simulation results show that the new Maximum C/I scheme outperforms the conventional scheme in throughput performance and delay performance, and that the FER decreases faster as the maximum number of the retransmission increases.
Analytical expressions for maximum wind turbine average power in a Rayleigh wind regime
Carlin, P.W.
1996-12-01
Average or expectation values for annual power of a wind turbine in a Rayleigh wind regime are calculated and plotted as a function of cut-out wind speed. This wind speed is expressed in multiples of the annual average wind speed at the turbine installation site. To provide a common basis for comparison of all real and imagined turbines, the Rayleigh-Betz wind machine is postulated. This machine is an ideal wind machine operating with the ideal Betz power coefficient of 0.593 in a Rayleigh probability wind regime. All other average annual powers are expressed in fractions of that power. Cases considered include: (1) an ideal machine with finite power and finite cutout speed, (2) real machines operating in variable speed mode at their maximum power coefficient, and (3) real machines operating at constant speed.
High-Speed Superconductive Decimation Filter for Sigma-Delta Analog to Digital Converter
Wakamatsu, Tomu; Yamanashi, Yuki; Yoshikawa, Nobuyuki
2017-07-01
A superconducting decimation filter is required to convert high-speed output data from a superconducting sigma-delta analog to digital (A/D) modulator to low-speed data for data acquisition by room-temperature electronics. Because the operating frequency of the conventional superconducting decimation filter is lower than that of the maximum operation frequency of A/D modulator, the system performance of the superconducting A/D converter is limited by the decimation filter. We propose a decimation filter that can operate at the sampling frequency of the A/D modulator by hybridizing a shift-register-based and a counter-based decimation filters. The investigated decimation filter can be implemented with a practical circuit area. We designed and tested the investigated decimation filter. The simulation result indicates that the maximum operation frequency of the designed decimation filter is 39.8 GHz assuming the 2.5 kA/cm2 Nb fabrication process. We experimentally confirmed the low-speed operation of the designed decimation filter with the bias margin of 93.8%-110.8%.
Ultrahigh-Speed Optical Transmission Technology
Weber, Hans-Georg
2007-01-01
Ultrahigh-speed optical transmission technology is a key technology for increasing the communication capacity. In optical fibre networks, the number of wavelength channels and the bit rate per wavelength channel, i.e. the TDM (Time Division Multiplexing) bit rate, determine the transmission capacity. Currently, TDM bit rates of more than 40 Gbit/s require optical signal processing (Optical Time Division Multiplexing, OTDM). OTDM bit rates of up to 1.2 Tbit/s have already been reported. The devices developed for ultrahigh-speed optical transmission are not limited to communication applications only. They are key devices for high-speed optical signal processing, i.e. monitoring, measurement and control, and will thus give a wide technological basis for innovative science and technology. All these aspects of ultrahigh-speed optical transmission technology are described in detail in this book.
Variable Speed Rotor System Project
National Aeronautics and Space Administration — Variable speed rotors will give helicopters several advantages: higher top speed, greater fuel efficiency, momentary emergency over-power, resonance detuning...
Vadeby, Anna; Forsman, Åsa
2017-06-01
This study investigated the effect of applying two aggregated models (the Power model and the Exponential model) to individual vehicle speeds instead of mean speeds. This is of particular interest when the measure introduced affects different parts of the speed distribution differently. The aim was to examine how the estimated overall risk was affected when assuming the models are valid on an individual vehicle level. Speed data from two applications of speed measurements were used in the study: an evaluation of movable speed cameras and a national evaluation of new speed limits in Sweden. The results showed that when applied on individual vehicle speed level compared with aggregated level, there was essentially no difference between these for the Power model in the case of injury accidents. However, for fatalities the difference was greater, especially for roads with new cameras where those driving fastest reduced their speed the most. For the case with new speed limits, the individual approach estimated a somewhat smaller effect, reflecting that changes in the 15th percentile (P15) were somewhat larger than changes in P85 in this case. For the Exponential model there was also a clear, although small, difference between applying the model to mean speed changes and individual vehicle speed changes when speed cameras were used. This applied both for injury accidents and fatalities. There were also larger effects for the Exponential model than for the Power model, especially for injury accidents. In conclusion, applying the Power or Exponential model to individual vehicle speeds is an alternative that provides reasonable results in relation to the original Power and Exponential models, but more research is needed to clarify the shape of the individual risk curve. It is not surprising that the impact on severe traffic crashes was larger in situations where those driving fastest reduced their speed the most. Further investigations on use of the Power and/or the
Richard TAY
2003-01-01
Full Text Available While there has been extensive research on the effect of sensation seeking on risky driving, relatively little research has been conducted on Type-A personality. The motivations for speeding are likely to be different for each group and these differences have important implications for the design, implementation and expected efficacy of road safety countermeasures. This paper examines the influence of sensation seeking and Type-A behavior pattern on speeding behaviour. A sample of 139 staff and students in an Australian university were surveyed in July 2001 to gather information on their gender, age, personality and self-reported speeding behaviour. The data were analysed using correlations and analysis of variance procedures. Finally, some implications for road safety are discussed.
Mechanical versus physiological determinants of swimming speeds in diving Brünnich's guillemots.
Lovvorn, J R; Croll, D A; Liggins, G A
1999-07-01
For fast flapping flight of birds in air, the maximum power and efficiency of the muscles occur over a limited range of contraction speeds and loads. Thus, contraction frequency and work per stroke tend to stay constant for a given species. In birds such as auks (Alcidae) that fly both in air and under water, wingbeat frequencies in water are far lower than in air, and it is unclear to what extent contraction frequency and work per stroke are conserved. During descent, compression of air spaces dramatically lowers buoyant resistance, so that maintaining a constant contraction frequency and work per stroke should result in an increased swimming speed. However, increasing speed causes exponential increases in drag, thereby reducing mechanical versus muscle efficiency. To investigate these competing factors, we have developed a biomechanical model of diving by guillemots (Uria spp.). The model predicted swimming speeds if stroke rate and work per stroke stay constant despite changing buoyancy. We compared predicted speeds with those of a free-ranging Brünnich's guillemot (U. lomvia) fitted with a time/depth recorder. For descent, the model predicted that speed should gradually increase to an asymptote of 1.5-1.6 m s-1 at approximately 40 m depth. In contrast, the instrumented guillemot typically reached 1.5 m s-1 within 10 m of the water surface and maintained that speed throughout descent to 80 m. During ascent, the model predicted that guillemots should stroke steadily at 1.8 m s-1 below their depth of neutral buoyancy (62 m), should alternate stroking and gliding at low buoyancies from 62 to 15 m, and should ascend passively by buoyancy alone above 15 m depth. However, the instrumented guillemot typically ascended at 1.25 m s-1 when negatively buoyant, at approximately 1.5 m s-1 from 62 m to 25 m, and supplemented buoyancy with stroking above 25 m. Throughout direct descent, and during ascent at negative and low positive buoyancies (82-25 m), the guillemot
[Study on the maximum entropy principle and population genetic equilibrium].
Zhang, Hong-Li; Zhang, Hong-Yan
2006-03-01
A general mathematic model of population genetic equilibrium about one locus was constructed based on the maximum entropy principle by WANG Xiao-Long et al. They proved that the maximum solve of the model was just the frequency distribution that a population reached Hardy-Weinberg genetic equilibrium. It can suggest that a population reached Hardy-Weinberg genetic equilibrium when the genotype entropy of the population reached the maximal possible value, and that the frequency distribution of the maximum entropy was equivalent to the distribution of Hardy-Weinberg equilibrium law about one locus. They further assumed that the frequency distribution of the maximum entropy was equivalent to all genetic equilibrium distributions. This is incorrect, however. The frequency distribution of the maximum entropy was only equivalent to the distribution of Hardy-Weinberg equilibrium with respect to one locus or several limited loci. The case with regard to limited loci was proved in this paper. Finally we also discussed an example where the maximum entropy principle was not the equivalent of other genetic equilibria.
On some problems of the maximum entropy ansatz
K Bandyopadhyay; K Bhattacharyya; A K Bhattacharyya
2000-03-01
Some problems associated with the use of the maximum entropy principle, namely, (i) possible divergence of the series that is exponentiated, (ii) input-dependent asymptotic behaviour of the density function resulting from the truncation of the said series, and (iii) non-vanishing of the density function at the boundaries of a ﬁnite domain are pointed out. Prescriptions for remedying the aforesaid problems are put forward. Pilot calculations involving the ground quantum eigenenergy states of the quartic oscillator, the particle-in-a-box model, and the classical Maxwellian speed and energy distributions lend credence to our approach.
BLADE SECTION DESIGN OF MARINE PROPELLERS WITH MAXIMUM CAVITATION INCEPTION SPEED
ZENG Zhi-bo; KUIPER Gert
2012-01-01
Kuiper and Jessup (1993) developed a design method for propellers in a wake based on the Eppler foil design method.The optimized section is transformed into the three-dimensional propeller flow using the approach of the effective blade sections.Effective blade sections are two-dimensional sections in two-dimensional flow which have the same chordwise loading distribution as the three-dimensional blade sections of a propeller.However,the design procedure is laborious in two aspects:finding an optimum blade section using the Eppler program requires much skill of the designer,and transforming the two-dimensional blade section into a propeller blade section in three-dimensional flow is complex.In this work,these two problems were coped with.A blade section design procedure was presented using an optimization technique and an alternative procedure for the effective blade section is developed using a lifting surface design method.To validate the method a benchmark model of a naval ship was used.This benchmark model was extended by new appendices and a reference propeller,and designed using conventional design methods.This reference propeller was optimized using the new design procedure and model tests were carried out.Special attention was given to the data of the model and the reference propeller,to make the configuration suitable for the Reynolds-Averaged Navier-Stokes (RANS) calculations.
Maximum-power quantum-mechanical Carnot engine.
Abe, Sumiyoshi
2011-04-01
In their work [J. Phys. A 33, 4427 (2000)], Bender, Brody, and Meister have shown by employing a two-state model of a particle confined in the one-dimensional infinite potential well that it is possible to construct a quantum-mechanical analog of the Carnot engine through changes of both the width of the well and the quantum state in a specific manner. Here, a discussion is developed about realizing the maximum power of such an engine, where the width of the well moves at low but finite speed. The efficiency of the engine at the maximum power output is found to be universal independently of any of the parameters contained in the model.
Limits and Signatures of Relativistic Spaceflight
Yurtsever, Ulvi
2015-01-01
While special relativity imposes an absolute speed limit at the speed of light, our Universe is not empty Minkowski spacetime. The constituents that fill the interstellar/intergalactic vacuum, including the cosmic microwave background photons, impose a lower speed limit on any object travelling at relativistic velocities. Scattering of cosmic microwave phtotons from an ultra-relativistic object may create radiation with a characteristic signature allowing the detection of such objects at large distances.
Combining Experiments and Simulations Using the Maximum Entropy Principle
Boomsma, Wouter; Ferkinghoff-Borg, Jesper; Lindorff-Larsen, Kresten
2014-01-01
are not in quantitative agreement with experimental data. The principle of maximum entropy is a general procedure for constructing probability distributions in the light of new data, making it a natural tool in cases when an initial model provides results that are at odds with experiments. The number of maximum entropy...... in the context of a simple example, after which we proceed with a real-world application in the field of molecular simulations, where the maximum entropy procedure has recently provided new insight. Given the limited accuracy of force fields, macromolecular simulations sometimes produce results....... Three very recent papers have explored this problem using the maximum entropy approach, providing both new theoretical and practical insights to the problem. We highlight each of these contributions in turn and conclude with a discussion on remaining challenges....
OVER SPEED VIOLATION MANAGEMENT OF A VEHICLE THROUGH ZIGBEE
Uma Makeswari.A
2013-02-01
Full Text Available In the present day scenario traffic rules are frequently violated by the drivers and over speeding occur due to bad driving behavior. So, a driver assistance system is provided to prevent over speeding,violation of road rules and also to display alert messages. The proposed system has an alerting, recording and reporting system for over speed violation management. The Zigbee transmitter sends the speed limit of the particular lane entered by the vehicle and also gives alerts like “road works”, “steep slopes”, “school zone” in the form of acoustical messages and also in LCD. The receiver unit placed in the vehicle receives the messages and sends to the microcontroller. When speed of the vehicle nears the speed limit itdisplays the warning and if exceeds the limit, the microcontroller records the violated speed and time. The LCD displays the lane speed limit and shows the number of times, speed was violated. A GSMmodule sends message to the nearest traffic personnel immediately after a violation occurs. An authenticated device is also provided, which can be operated only by the traffic police in which he canretrieve the data stored at any time. Increase in the count of violation increases the penalty amount which can be collected in toll gates located nearby.
Intelligent Speed Adaptation (ISA) and Road Safety.
Oei, H.L. & Polak, P.H.
2002-01-01
An ISA system consists of GPS to determine the car's position, a CD-ROM in the car containing information of a road network including the prevailing speed limit of each road section, and feedback to the driver, Experiments in Sweden are testing several options, from warning the driver, to resisting
32 CFR 636.22 - Speed regulations.
2010-07-01
.... (2) The authorized speed limit in the school zones is 15 miles per hour when any of the following conditions are present: (i) A school crossing attendant is present. (ii) Children are present in the area... MPH Night Driving: Trails, 5 MPH (with headlights) Cross Country, 5 MPH Night Driving: Trails, 4...
Intelligent Speed Adaptation (ISA) and Road Safety.
Oei, H.L. & Polak, P.H.
2002-01-01
An ISA system consists of GPS to determine the car's position, a CD-ROM in the car containing information of a road network including the prevailing speed limit of each road section, and feedback to the driver, Experiments in Sweden are testing several options, from warning the driver, to resisting
A probabilistic approach to the concept of Probable Maximum Precipitation
Papalexiou, S. M.; D. Koutsoyiannis
2006-01-01
International audience; The concept of Probable Maximum Precipitation (PMP) is based on the assumptions that (a) there exists an upper physical limit of the precipitation depth over a given area at a particular geographical location at a certain time of year, and (b) that this limit can be estimated based on deterministic considerations. The most representative and widespread estimation method of PMP is the so-called moisture maximization method. This method maximizes observed storms assuming...
The Maximum Patch Method for Directional Dark Matter Detection
Henderson, Shawn; Fisher, Peter
2008-01-01
Present and planned dark matter detection experiments search for WIMP-induced nuclear recoils in poorly known background conditions. In this environment, the maximum gap statistical method provides a way of setting more sensitive cross section upper limits by incorporating known signal information. We give a recipe for the numerical calculation of upper limits for planned directional dark matter detection experiments, that will measure both recoil energy and angle, based on the gaps between events in two-dimensional phase space.
Mateus Barancelli Schwedersky
2011-12-01
Full Text Available O processo TIG, em configurações tradicionais, apresenta problemas quando utilizado de maneira autógena com elevadas corrente e velocidade de soldagem. Nessa condição, normalmente ocorrem defeitos no cordão, principalmente descontinuidades denominadas humping. Em estudo realizado no LABSOLDA, foram obtidas soldas de excelente qualidade com o processo TIG atingindo velocidades de 1,5 m/min. Este procedimento, utilizando na proteção misturas argônio-hidrogênio, possibilitou velocidade semelhante ao processo MIG/MAG convencional, com a vantagem de ser realizada sem material de adição. O presente trabalho tem o objetivo de fornecer subsídios para uma nova análise da formação dos defeitos na soldagem TIG de elevada produtividade, já que a teoria baseada na pressão do arco não contempla totalmente o que tem sido observado na prática. Foram realizados ensaios com diferentes correntes utilizando argônio, hélio e misturas argônio-hidrogênio no gás de proteção. Os resultados mostram que para a mesma corrente média, à medida que o teor de H2 foi aumentado, ocorreram também gradativos aumentos da área fundida e eficiência de fusão. Foi possível mostrar indícios de que o mecanismo de formação de defeitos não depende somente da pressão do arco, mas sim do balanço entre pressão do arco e quantidade de metal fundido, que é dependente da eficiência de fusão proporcionada pelo gás utilizado.Under usual configurations, the TIG process presents problems when used autogenously with high current and welding speed. In this condition defects in the weld bead usually occur, especially discontinuities called humping. In a study conducted at LABSOLDA, welds with excellent quality were obtained using the TIG process reaching speeds of 1.5 m/min. Under argon-hydrogen shielding gas mixtures welding speed similar to the conventional MIG/MAG process was allowed, with the advantage of being performed without filler material. The
Spindle picker harvest speed effects
The gear drive of a modern John Deere Pro 16 picker unit was modified so that spindle speed was reduced without changing the drum speed. Three 1-row picking units were used in the study, one with the standard drive speeds, one with 25% reduction in spindle drive speed, and one with 50% reduction in...
Sørensen, Flemming; Mattsson, Jan
2016-01-01
Minimisation of time-to-market strategies can provide companies with a competitive advantage in dynamic and competitive environments. Using parallel innovation processes has been emphasised as one strategy to speed up innovation processes and consequently minimise the time-to-market of innovations...
2008-01-01
Following more than 10 years of deliberation and planning,construc- tion of the 1,320-km Beijing-Shanghai High-speed Railway began in mid- April.Following the world’s most elevated Qinghai-Tibet Railway,which
Boldea, Ion
2005-01-01
With the deregulation of electrical energy production and distribution, says Boldea (Polytechnical Institute, Timisoara, Romania) producers are looking for ways to tailor their electricity for different markets. Variable-speed electric generators are serving that purpose, up to the 400 megavolt ampere unit size, in Japan since 1996 and Germany sinc
V. Fung
2013-10-01
Full Text Available Changing cloud cover is a major source of solar radiation variability and poses challenges for the integration of solar energy. A compact and economical system that measures cloud motion vectors to estimate power plant ramp rates and provide short term solar irradiance forecasts is presented. The Cloud Speed Sensor (CSS is constructed using an array of luminance sensors and high-speed data acquisition to resolve the progression of cloud passages across the sensor footprint. An embedded microcontroller acquires the sensor data and uses a cross-correlation algorithm to determine cloud motion vectors. The CSS was validated against an artificial shading test apparatus, an alternative method of cloud motion detection from ground measured irradiance (Linear Cloud Edge, LCE, and a UC San Diego Sky Imager (USI. The CSS detected artificial shadow directions and speeds to within 15 and 6% accuracy, respectively. The CSS detected (real cloud directions and speeds without average bias and with average weighted root mean square difference of 22° and 1.9 m s−1 when compared to USI and 33° and 1.5 m s−1 when compared to LCE results.
Stoddard, Edward
1994-01-01
Entertaining, easy-to-follow suggestions for developing greater speed and accuracy in doing mathematical calculations. Surefire methods for multiplying without carrying, dividing with half the pencil work of long division, plus advice on how to add and subtract rapidly, master fractions, work quickly with decimals, handle percentages, and much more.
Speed estimator for induction motor drive based on synchronous speed tracking
S B Bodkhe; M V Aware; J G Chaudhari; J G Agrawal
2015-06-01
This paper presents a new open-loop speed estimation method for a three-phase induction motor drive. The open-loop speed estimators available in literature have the advantage of reduced computational stress over the observers but they share a common limitation of being largely dependent on flux and machine parameters. They involve integrations and differentiation in the algorithm that leads to serious error in estimation when subject to different operating conditions. The proposed estimator is based on synchronous speed tracking and is cost-effective. It is immune to any variation in machine parameters and noise. The synchronous speed is computed from stator frequency which is estimated on-line using the stator current signals. A unique, non-adaptive method for estimation of stator frequency within one-sixteenth of time period is also proposed to enhance the speed of estimation. Computer simulation and experimentation on a 2.2 kW Field oriented controlled induction motor drive is carried out to verify the performance of proposed speed estimator. The results show excellent response over a wide range of rotor speed in both directions including low speed and under different operating conditions. This confirms the effectiveness of the proposed method.
Two methods for estimating limits to large-scale wind power generation.
Miller, Lee M; Brunsell, Nathaniel A; Mechem, David B; Gans, Fabian; Monaghan, Andrew J; Vautard, Robert; Keith, David W; Kleidon, Axel
2015-09-08
Wind turbines remove kinetic energy from the atmospheric flow, which reduces wind speeds and limits generation rates of large wind farms. These interactions can be approximated using a vertical kinetic energy (VKE) flux method, which predicts that the maximum power generation potential is 26% of the instantaneous downward transport of kinetic energy using the preturbine climatology. We compare the energy flux method to the Weather Research and Forecasting (WRF) regional atmospheric model equipped with a wind turbine parameterization over a 10(5) km2 region in the central United States. The WRF simulations yield a maximum generation of 1.1 We⋅m(-2), whereas the VKE method predicts the time series while underestimating the maximum generation rate by about 50%. Because VKE derives the generation limit from the preturbine climatology, potential changes in the vertical kinetic energy flux from the free atmosphere are not considered. Such changes are important at night when WRF estimates are about twice the VKE value because wind turbines interact with the decoupled nocturnal low-level jet in this region. Daytime estimates agree better to 20% because the wind turbines induce comparatively small changes to the downward kinetic energy flux. This combination of downward transport limits and wind speed reductions explains why large-scale wind power generation in windy regions is limited to about 1 We⋅m(-2), with VKE capturing this combination in a comparatively simple way.
Quantum-dot Carnot engine at maximum power.
Esposito, Massimiliano; Kawai, Ryoichi; Lindenberg, Katja; Van den Broeck, Christian
2010-04-01
We evaluate the efficiency at maximum power of a quantum-dot Carnot heat engine. The universal values of the coefficients at the linear and quadratic order in the temperature gradient are reproduced. Curzon-Ahlborn efficiency is recovered in the limit of weak dissipation.
33 CFR 401.3 - Maximum vessel dimensions.
2010-07-01
..., and having dimensions that do not exceed the limits set out in the block diagram in appendix I of this... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Maximum vessel dimensions. 401.3 Section 401.3 Navigation and Navigable Waters SAINT LAWRENCE SEAWAY DEVELOPMENT CORPORATION, DEPARTMENT...
Naturalistic speeding data: Drivers aged 75 years and older
Anna Chevalier
2016-09-01
Full Text Available The data presented in this article are related to the research article entitled “A longitudinal investigation of the predictors of older drivers׳ speeding behavior” (Chevalier et al., 2016 [1], wherein these speed events were used to investigate older drivers speeding behavior and the influence of cognition, vision, functional decline, and self-reported citations and crashes on speeding behavior over a year of driving. Naturalistic speeding behavior data were collected for up to 52 weeks from volunteer drivers aged 75–94 years (median 80 years, 52% male living in the suburban outskirts of Sydney. Driving data were collected using an in-vehicle monitoring device. Global Positioning System (GPS data were recorded at each second and determined driving speed through triangulation of satellite collected location data. Driving speed data were linked with mapped speed zone data based on a service-provider database. To measure speeding behavior, speed events were defined as driving 1 km/h or more, with a 3% tolerance, above a single speed limit, averaged over 30 s. The data contains a row per 124,374 speed events. This article contains information about data processing and quality control.
Naturalistic speeding data: Drivers aged 75 years and older.
Chevalier, Anna; Chevalier, Aran John; Clarke, Elizabeth; Wall, John; Coxon, Kristy; Brown, Julie; Ivers, Rebecca; Keay, Lisa
2016-09-01
The data presented in this article are related to the research article entitled "A longitudinal investigation of the predictors of older drivers׳ speeding behavior" (Chevalier et al., 2016) [1], wherein these speed events were used to investigate older drivers speeding behavior and the influence of cognition, vision, functional decline, and self-reported citations and crashes on speeding behavior over a year of driving. Naturalistic speeding behavior data were collected for up to 52 weeks from volunteer drivers aged 75-94 years (median 80 years, 52% male) living in the suburban outskirts of Sydney. Driving data were collected using an in-vehicle monitoring device. Global Positioning System (GPS) data were recorded at each second and determined driving speed through triangulation of satellite collected location data. Driving speed data were linked with mapped speed zone data based on a service-provider database. To measure speeding behavior, speed events were defined as driving 1 km/h or more, with a 3% tolerance, above a single speed limit, averaged over 30 s. The data contains a row per 124,374 speed events. This article contains information about data processing and quality control.
E-Speed Governors For Public Transport Vehicles
Sridhar, C S; Kumar, S Madhava; Sridhar, Manjula; D, Varun
2010-01-01
An accident is unexpected, unusual, unintended and identifiable external event which occurs at any place and at any time. The major concern faced by the government and traffic officials is over speeding at limited speed zones like hospitals, schools or residential places leading to causalities and more deaths on the roads. Hence the speed of the vehicles is to be regulated and confined to the limits as prescribed by the traffic regulations. In this paper we propose a solution in the form of providing E-speed governor fitted with a wireless communication system consisting of a Rx which receives the information regarding the speed regulation for their zones. The TX will be made highly intelligent and decide when receiver should be made active to regulate the speed and unwarranted honking from the vehicles which can be deactivated in the silent zones.
Wind speed vertical distribution at Mt. Graham
Hagelin, S; Lascaux, F
2010-01-01
The characterization of the wind speed vertical distribution V(h) is fundamental for an astronomical site for many different reasons: (1) the wind speed shear contributes to trigger optical turbulence in the whole troposphere, (2) a few of the astroclimatic parameters such as the wavefront coherence time (tau_0) depends directly on V(h), (3) the equivalent velocity V_0, controlling the frequency at which the adaptive optics systems have to run to work properly, depends on the vertical distribution of the wind speed and optical turbulence. Also, a too strong wind speed near the ground can introduce vibrations in the telescope structures. The wind speed at a precise pressure (200 hPa) has frequently been used to retrieve indications concerning the tau_0 and the frequency limits imposed to all instrumentation based on adaptive optics systems, but more recently it has been proved that V_200 (wind speed at 200 hPa) alone is not sufficient to provide exhaustive elements concerning this topic and that the vertical d...
Sensor study for high speed autonomous operations
Schneider, Anne; La Celle, Zachary; Lacaze, Alberto; Murphy, Karl; Del Giorno, Mark; Close, Ryan
2015-06-01
As robotic ground systems advance in capabilities and begin to fulfill new roles in both civilian and military life, the limitation of slow operational speed has become a hindrance to the wide-spread adoption of these systems. For example, military convoys are reluctant to employ autonomous vehicles when these systems slow their movement from 60 miles per hour down to 40. However, these autonomous systems must operate at these lower speeds due to the limitations of the sensors they employ. Robotic Research, with its extensive experience in ground autonomy and associated problems therein, in conjunction with CERDEC/Night Vision and Electronic Sensors Directorate (NVESD), has performed a study to specify system and detection requirements; determined how current autonomy sensors perform in various scenarios; and analyzed how sensors should be employed to increase operational speeds of ground vehicles. The sensors evaluated in this study include the state of the art in LADAR/LIDAR, Radar, Electro-Optical, and Infrared sensors, and have been analyzed at high speeds to study their effectiveness in detecting and accounting for obstacles and other perception challenges. By creating a common set of testing benchmarks, and by testing in a wide range of real-world conditions, Robotic Research has evaluated where sensors can be successfully employed today; where sensors fall short; and which technologies should be examined and developed further. This study is the first step to achieve the overarching goal of doubling ground vehicle speeds on any given terrain.
Receiver function estimated by maximum entropy deconvolution
吴庆举; 田小波; 张乃铃; 李卫平; 曾融生
2003-01-01
Maximum entropy deconvolution is presented to estimate receiver function, with the maximum entropy as the rule to determine auto-correlation and cross-correlation functions. The Toeplitz equation and Levinson algorithm are used to calculate the iterative formula of error-predicting filter, and receiver function is then estimated. During extrapolation, reflective coefficient is always less than 1, which keeps maximum entropy deconvolution stable. The maximum entropy of the data outside window increases the resolution of receiver function. Both synthetic and real seismograms show that maximum entropy deconvolution is an effective method to measure receiver function in time-domain.
Effects of High-Speed Power Training on Muscle Performance and Braking Speed in Older Adults
Stephen P. Sayers
2012-01-01
Full Text Available We examined whether high-speed power training (HSPT improved muscle performance and braking speed using a driving simulator. 72 older adults (22 m, 50 f; age = 70.6 ± 7.3 yrs were randomized to HSPT at 40% one-repetition maximum (1RM (HSPT: n=25; 3 sets of 12–14 repetitions, slow-speed strength training at 80%1RM (SSST: n=25; 3 sets of 8–10 repetitions, or control (CON: n=22; stretching 3 times/week for 12 weeks. Leg press and knee extension peak power, peak power velocity, peak power force/torque, and braking speed were obtained at baseline and 12 weeks. HSPT increased peak power and peak power velocity across a range of external resistances (40–90% 1RM; P<0.05 and improved braking speed (P<0.05. Work was similar between groups, but perceived exertion was lower in HSPT (P<0.05. Thus, the less strenuous HSPT exerted a broader training effect and improved braking speed compared to SSST.
An Analysis of Variable-Speed Wind Turbine Power-Control Methods with Fluctuating Wind Speed
Seung-Il Moon
2013-07-01
Full Text Available Variable-speed wind turbines (VSWTs typically use a maximum power-point tracking (MPPT method to optimize wind-energy acquisition. MPPT can be implemented by regulating the rotor speed or by adjusting the active power. The former, termed speed-control mode (SCM, employs a speed controller to regulate the rotor, while the latter, termed power-control mode (PCM, uses an active power controller to optimize the power. They are fundamentally equivalent; however, since they use a different controller at the outer control loop of the machine-side converter (MSC controller, the time dependence of the control system differs depending on whether SCM or PCM is used. We have compared and analyzed the power quality and the power coefficient when these two different control modes were used in fluctuating wind speeds through computer simulations. The contrast between the two methods was larger when the wind-speed fluctuations were greater. Furthermore, we found that SCM was preferable to PCM in terms of the power coefficient, but PCM was superior in terms of power quality and system stability.
New tests of variability of the speed of light.
Dąbrowski Mariusz P.
2016-01-01
Full Text Available We present basic ideas of the varying speed of light cosmology, its formulation, benefits and problems. We relate it to the theories of varying fine structure constants and discuss some new tests (redshift drift and angular diameter distance maximum which may allow measuring timely and spatial change of the speed of light by using the future missions such as Euclid, SKA (Square Kilometer Array or others.
New tests of variability of the speed of light.
Dąbrowski Mariusz P.; Salzano Vincenzo; Balcerzak Adam; Lazkoz Ruth
2016-01-01
We present basic ideas of the varying speed of light cosmology, its formulation, benefits and problems. We relate it to the theories of varying fine structure constants and discuss some new tests (redshift drift and angular diameter distance maximum) which may allow measuring timely and spatial change of the speed of light by using the future missions such as Euclid, SKA (Square Kilometer Array) or others.
Exploring the Quantum Speed Limit with Computer Games
Sørensen, Jens Jakob Winther Hedemann; Pedersen, Mads Kock; Munch, Michael Kulmback
2016-01-01
scientists and allowing them to provide novel solutions to the research problems. Citizen science games have been used successfully in Foldit, EteRNA and EyeWire to study protein and RNA folding and neuron mapping. However, gamification has never been applied in quantum physics. Everyday experiences of non......-experts are based on classical physics and it is \\textit{a priori} not clear that they should have an intuition for quantum dynamics. Does this premise hinder the use of citizen scientists in the realm of quantum mechanics? Here we report on Quantum Moves, an online platform gamifying optimization problems...... in quantum physics. Quantum Moves aims to use human players to find solutions to a class of problems associated with quantum computing. Players discover novel solution strategies which numerical optimizations fail to find. Guided by player strategies, a new low-dimensional heuristic optimization method...
Speed limit of the insulator-metal transition in magnetite
de Jong, S.; Kukreja, R.; Trabant, C.; Pontius, N.; Chang, C.F.; Kachel, T.; Beye, M.; Sorgenfrei, F.; Back, C.H.; Bräuer, B..; Schlotter, W.F.; Turner, J.J.; Krupin, O.; Doehler, M.; Zhu, D.; Hossain, M.A.; Scherz, A.O.; Fausti, D.; Novelli, F.; Esposito, M.; Lee, W.S.; Chuang, Y.D.; Lu, D.H.; Moore, R.G.; Yi, M.; Trigo, M.; Kirchmann, P.; Pathey, L.; Golden, M.; Bucholtz, M.; Metcalf, P.; Parmigiani, F.; Wurth, W.; Föhlisch, A.; Schüßler-Langeheine, C.; Dürr, H.A.
2013-01-01
As the oldest known magnetic material, magnetite (Fe3O4) has fascinated mankind for millennia. As the first oxide in which a relationship between electrical conductivity and fluctuating/localized electronic order was shown1, magnetite represents a model system for understanding correlated oxides in